diff --git a/src/components/Roof2.jsx b/src/components/Roof2.jsx
index 20883410..68303710 100644
--- a/src/components/Roof2.jsx
+++ b/src/components/Roof2.jsx
@@ -4,13 +4,20 @@ import { Mode, useMode } from '@/hooks/useMode'
 import { Button } from '@nextui-org/react'
 import RangeSlider from './ui/RangeSlider'
 import { useRecoilState, useRecoilValue } from 'recoil'
-import { canvasSizeState, fontSizeState, roofMaterialState, sortedPolygonArray, templateTypeState, compassState } from '@/store/canvasAtom'
+import {
+  canvasSizeState,
+  compassState,
+  fontSizeState,
+  roofMaterialState,
+  roofState,
+  sortedPolygonArray,
+  templateTypeState,
+  wallState,
+} from '@/store/canvasAtom'
 import { QLine } from '@/components/fabric/QLine'
 import { getCanvasState, insertCanvasState } from '@/lib/canvas'
 import { calculateIntersection } from '@/util/canvas-util'
 import { QPolygon } from '@/components/fabric/QPolygon'
-import * as turf from '@turf/turf'
-import { toGeoJSON } from '@/util/qpolygon-utils'
 
 export default function Roof2() {
   const { canvas, handleRedo, handleUndo, setCanvasBackgroundWithDots, saveImage, addCanvas } = useCanvas('canvas')
@@ -38,6 +45,10 @@ export default function Roof2() {
 
   const [compass, setCompass] = useRecoilState(compassState)
 
+  const roof = useRecoilValue(roofState)
+
+  const wall = useRecoilValue(wallState)
+
   const {
     mode,
     setMode,
@@ -55,6 +66,8 @@ export default function Roof2() {
     createRoofRack,
     drawRoofPolygon,
     drawCellInTrestle,
+    setDirectionTrestles,
+    cutHelpLines,
   } = useMode()
 
   // const [canvasState, setCanvasState] = useRecoilState(canvasAtom)
@@ -553,12 +566,19 @@ export default function Roof2() {
             <Button className="m-1 p-2" color={`${mode === Mode.TEXTBOX ? 'primary' : 'default'}`} onClick={() => setMode(Mode.TEXTBOX)}>
               텍스트박스 모드
             </Button>
-            {/*<Button className="m-1 p-2" onClick={handleUndo}>
+            <Button
+              className="m-1 p-2"
+              color={`${mode === Mode.DRAW_HELP_LINE ? 'primary' : 'default'}`}
+              onClick={() => setMode(Mode.DRAW_HELP_LINE)}
+            >
+              보조선 연결 모드
+            </Button>
+            <Button className="m-1 p-2" onClick={handleUndo}>
               Undo
             </Button>
             <Button className="m-1 p-2" onClick={handleRedo}>
               Redo
-            </Button>*/}
+            </Button>
             <Button className="m-1 p-2" onClick={handleClear}>
               clear
             </Button>
@@ -614,6 +634,9 @@ export default function Roof2() {
             <Button className="m-1 p-2" onClick={addCanvas}>
               캔버스 추가
             </Button>*/}
+            <Button className="m-1 p-2" onClick={cutHelpLines}>
+              보조선 절삭
+            </Button>
             {templateType === 1 && (
               <>
                 <Button className="m-1 p-2" onClick={drawRoofMaterial}>
@@ -622,6 +645,9 @@ export default function Roof2() {
                 <Button className="m-1 p-2" onClick={createRoofRack}>
                   지붕가대설치
                 </Button>
+                <Button className="m-1 p-2" onClick={setDirectionTrestles}>
+                  가대 방향 설정
+                </Button>
                 <Button className="m-1 p-2" onClick={drawCellInTrestle}>
                   선택한 가대 셀채우기
                 </Button>
diff --git a/src/hooks/useCanvas.js b/src/hooks/useCanvas.js
index 968f3676..27c80187 100644
--- a/src/hooks/useCanvas.js
+++ b/src/hooks/useCanvas.js
@@ -1,6 +1,6 @@
 import { useEffect, useRef, useState } from 'react'
 import { fabric } from 'fabric'
-import { actionHandler, anchorWrapper, polygonPositionHandler } from '@/util/canvas-util'
+import { actionHandler, anchorWrapper, calculateIntersection, distanceBetweenPoints, polygonPositionHandler } from '@/util/canvas-util'
 
 import { useRecoilState } from 'recoil'
 import { canvasSizeState, fontSizeState } from '@/store/canvasAtom'
@@ -9,6 +9,8 @@ import { QPolygon } from '@/components/fabric/QPolygon'
 import { defineQLine } from '@/util/qline-utils'
 import { defineQPloygon } from '@/util/qpolygon-utils'
 
+import * as turf from '@turf/turf'
+
 export function useCanvas(id) {
   const [canvas, setCanvas] = useState()
   const [isLocked, setIsLocked] = useState(false)
@@ -65,6 +67,7 @@ export function useCanvas(id) {
       initialize()
       canvas?.on('object:added', onChange)
       canvas?.on('object:added', addEventOnObject)
+
       canvas?.on('object:modified', onChange)
       canvas?.on('object:removed', onChange)
       canvas?.on('mouse:move', drawMouseLines)
diff --git a/src/hooks/useMode.js b/src/hooks/useMode.js
index 9edd121c..968c76ca 100644
--- a/src/hooks/useMode.js
+++ b/src/hooks/useMode.js
@@ -1,5 +1,13 @@
 import { useEffect, useRef, useState } from 'react'
-import { findTopTwoIndexesByDistance, getCenterPoint, getDirection, getStartIndex, rearrangeArray } from '@/util/canvas-util'
+import {
+  calculateIntersection,
+  distanceBetweenPoints,
+  findTopTwoIndexesByDistance,
+  getCenterPoint,
+  getDirection,
+  getStartIndex,
+  rearrangeArray,
+} from '@/util/canvas-util'
 import { useRecoilState, useRecoilValue } from 'recoil'
 
 import {
@@ -18,6 +26,8 @@ import { QLine } from '@/components/fabric/QLine'
 import { fabric } from 'fabric'
 import { QPolygon } from '@/components/fabric/QPolygon'
 import offsetPolygon from '@/util/qpolygon-utils'
+import { isObjectNotEmpty } from '@/util/common-utils'
+import * as turf from '@turf/turf'
 
 export const Mode = {
   DRAW_LINE: 'drawLine', // 기준선 긋기모드`
@@ -31,6 +41,7 @@ export const Mode = {
   ROOF_TRESTLE: 'roofTrestle', //지붕가대 모드
   FILL_CELLS: 'fillCells', //태양광셀 모드
   CELL_POWERCON: 'cellPowercon', //파워콘
+  DRAW_HELP_LINE: 'drawHelpLine', // 보조선 그리기 모드 지붕 존재해야함
   DEFAULT: 'default',
 }
 
@@ -254,6 +265,14 @@ export function useMode() {
       case 'cellPowercon':
         makeCellPowercon()
         break
+      case 'drawHelpLine':
+        canvas?.off('selection:created', addSelectCreatedEvent)
+        canvas?.off('selection:cleared', addSelectClearedEvent)
+        canvas?.on('selection:created', addSelectCreatedEvent)
+        canvas?.on('selection:cleared', addSelectClearedEvent)
+        drawHelpLineMode()
+        break
+
       case 'default':
         canvas?.off('mouse:down')
         break
@@ -340,6 +359,81 @@ export function useMode() {
     canvas?.renderAll()
   }
 
+  const addSelectCreatedEvent = (e) => {
+    const target = e.selected[0]
+
+    if (target.name === 'helpPoint') {
+      canvas?.on('mouse:move', helpPointEvent.mouseMove)
+    }
+  }
+
+  const helpPointEvent = {
+    mouseMove: (e) => {
+      const target = canvas?.getActiveObject()
+      const pointer = canvas?.getPointer(e.e)
+      const point = { x: target.left + target.radius, y: target.top + target.radius }
+      const angle = Math.atan2(pointer.y - point.y, pointer.x - point.x)
+      const degree = fabric.util.radiansToDegrees(angle)
+
+      const min = [0, 45, 90, -0, -90, -45, 135, -135, 180, -180].reduce((prev, curr) => {
+        return Math.abs(curr - degree) < Math.abs(prev - degree) ? curr : prev
+      })
+
+      // Calculate the center point of the target object
+      const centerX = target.left + target.width / 2
+      const centerY = target.top + target.height / 2
+
+      const length = distanceBetweenPoints(point, { x: pointer.x, y: pointer.y })
+
+      // min의 각도와 pointer의 위치를 이용하여 새로운 점을 구한다.
+      const newPoint = {
+        x: centerX + length * Math.cos(fabric.util.degreesToRadians(min)),
+        y: centerY + length * Math.sin(fabric.util.degreesToRadians(min)),
+      }
+
+      const line = new fabric.Line([point.x, point.y, newPoint.x, newPoint.y], {
+        stroke: 'black',
+        strokeWidth: 1,
+        selectable: false,
+        name: 'beforeHelpLine',
+        helpPoint: target,
+      })
+
+      const helpLines = canvas?._objects.filter((obj) => obj.name === 'beforeHelpLine')
+      helpLines.forEach((item) => canvas?.remove(item))
+
+      canvas?.add(line)
+    },
+  }
+
+  const addSelectClearedEvent = (e) => {
+    const target = e.deselected[0]
+
+    if (target.name === 'helpPoint') {
+      const beforeHelpLines = canvas?._objects.filter((obj) => obj.name === 'beforeHelpLine' && obj.helpPoint === target)
+
+      const helpLines = canvas?._objects.filter((obj) => obj.name === 'helpLine' && obj.helpPoint === target)
+
+      beforeHelpLines.forEach((item) => canvas?.remove(item))
+      helpLines.forEach((item) => canvas?.remove(item))
+
+      const newPoint = { x: beforeHelpLines[0].x2, y: beforeHelpLines[0].y2 }
+
+      const helpLine = new fabric.Line([target.left + target.radius, target.top + target.radius, newPoint.x, newPoint.y], {
+        stroke: 'red',
+        strokeWidth: 1,
+        selectable: false,
+        name: 'helpLine',
+        helpPoint: target,
+      })
+
+      canvas?.add(helpLine)
+      canvas?.renderAll()
+
+      canvas?.off('mouse:move', helpPointEvent.mouseMove)
+    }
+  }
+
   const handleKeyDown = (e) => {
     switch (e.key) {
       case 'ArrowDown': {
@@ -531,7 +625,7 @@ export function useMode() {
     // handleOuterlines()
     const wall = makePolygon(null, sort)
     wall.set({ name: 'wall' })
-    setWall(wall)
+    console.log('wall', wall)
 
     return wall
   }
@@ -695,6 +789,7 @@ export function useMode() {
         viewLengthText: true,
         fontSize: fontSize,
         sort: sort,
+        selectable: false,
       },
       canvas,
     )
@@ -738,296 +833,6 @@ export function useMode() {
     setZoom(Math.ceil(zoom - 10))
   }
 
-  const handleOuterlines = () => {
-    const newOuterlines = []
-    for (let i = 0; i < historyLines.current.length; i++) {
-      const next = historyLines.current[i + 1]
-      const prev = historyLines.current[i - 1] ?? historyLines.current[historyLines.current.length - 1]
-      if (next) {
-        if (next.direction === 'right') {
-          // 다름 라인이 오른쪽으로 이동
-          if (historyLines.current[i].direction === 'top') {
-            if (prev.direction !== 'right') {
-              if (historyLines.current.length === 4) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              } else if (historyLines.current.length === 6) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              } else if (historyLines.current.length === 8) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              }
-            } else {
-              newOuterlines.push({
-                x1: historyLines.current[i].x1 + 50,
-                y1: historyLines.current[i].y1 + 50,
-                x2: historyLines.current[i].x2 + 50,
-                y2: historyLines.current[i].y2 + 50,
-              })
-            }
-          } else {
-            // bottom
-            if (prev?.direction !== 'right') {
-              if (historyLines.current.length === 4) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              } else if (historyLines.current.length === 6) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              } else if (historyLines.current.length === 8) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              }
-            } else {
-              newOuterlines.push({
-                x1: historyLines.current[i].x1 - 50,
-                y1: historyLines.current[i].y1 + 50,
-                x2: historyLines.current[i].x2 - 50,
-                y2: historyLines.current[i].y2 + 50,
-              })
-            }
-          }
-        } else if (next.direction === 'left') {
-          if (historyLines.current[i].direction === 'top') {
-            if (prev?.direction !== 'left') {
-              if (historyLines.current.length === 4) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              } else if (historyLines.current.length === 6) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              } else if (historyLines.current.length === 8) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              }
-            } else {
-              newOuterlines.push({
-                x1: historyLines.current[i].x1 + 50,
-                y1: historyLines.current[i].y1 - 50,
-                x2: historyLines.current[i].x2 + 50,
-                y2: historyLines.current[i].y2 - 50,
-              })
-            }
-          } else {
-            // bottom
-            if (prev?.direction !== 'left') {
-              if (historyLines.current.length === 4) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              } else if (historyLines.current.length === 6) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              } else if (historyLines.current.length === 8) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              }
-            } else {
-              newOuterlines.push({
-                x1: historyLines.current[i].x1 - 50,
-                y1: historyLines.current[i].y1 - 50,
-                x2: historyLines.current[i].x2 - 50,
-                y2: historyLines.current[i].y2 - 50,
-              })
-            }
-          }
-        } else if (next.direction === 'top') {
-          if (historyLines.current[i].direction === 'right') {
-            if (prev?.direction !== 'top') {
-              if (historyLines.current.length === 4) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              } else if (historyLines.current.length === 6) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              } else if (historyLines.current.length === 8) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              }
-            } else {
-              newOuterlines.push({
-                x1: historyLines.current[i].x1 + 50,
-                y1: historyLines.current[i].y1 + 50,
-                x2: historyLines.current[i].x2 + 50,
-                y2: historyLines.current[i].y2 + 50,
-              })
-            }
-          } else {
-            // left
-            if (prev?.direction !== 'top') {
-              if (historyLines.current.length === 4) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              } else if (historyLines.current.length === 6) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              } else if (historyLines.current.length === 8) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              }
-            } else {
-              newOuterlines.push({
-                x1: historyLines.current[i].x1 + 50,
-                y1: historyLines.current[i].y1 - 50,
-                x2: historyLines.current[i].x2 + 50,
-                y2: historyLines.current[i].y2 - 50,
-              })
-            }
-          }
-        } else if (next.direction === 'bottom') {
-          if (historyLines.current[i].direction === 'right') {
-            if (prev?.direction !== 'bottom') {
-              if (historyLines.current.length === 4) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              } else if (historyLines.current.length === 6) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              } else if (historyLines.current.length === 8) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              }
-            } else {
-              newOuterlines.push({
-                x1: historyLines.current[i].x1 - 50,
-                y1: historyLines.current[i].y1 + 50,
-                x2: historyLines.current[i].x2 - 50,
-                y2: historyLines.current[i].y2 + 50,
-              })
-            }
-          } else {
-            // left
-            if (prev.direction !== 'bottom') {
-              if (historyLines.current.length === 4) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              } else if (historyLines.current.length === 6) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 + 50,
-                  y1: historyLines.current[i].y1 - 50,
-                  x2: historyLines.current[i].x2 - 50,
-                  y2: historyLines.current[i].y2 - 50,
-                })
-              } else if (historyLines.current.length === 8) {
-                newOuterlines.push({
-                  x1: historyLines.current[i].x1 - 50,
-                  y1: historyLines.current[i].y1 + 50,
-                  x2: historyLines.current[i].x2 + 50,
-                  y2: historyLines.current[i].y2 + 50,
-                })
-              }
-            } else {
-              newOuterlines.push({
-                x1: historyLines.current[i].x1 - 50,
-                y1: historyLines.current[i].y1 - 50,
-                x2: historyLines.current[i].x2 + 50,
-                y2: historyLines.current[i].y2 - 50,
-              })
-            }
-          }
-        }
-      } else {
-        const tmp = newOuterlines[newOuterlines.length - 1]
-        newOuterlines.push({
-          x1: tmp.x2,
-          y1: tmp.y2,
-          x2: newOuterlines[0].x1,
-          y2: newOuterlines[0].y1,
-        })
-      }
-    }
-
-    makePolygon(newOuterlines)
-  }
-
   /**
    *벽 지붕 외곽선 생성
    */
@@ -1115,9 +920,10 @@ export function useMode() {
     )
     roof.setWall(polygon)
     setRoof(roof)
+    setWall(polygon)
 
-    roof.drawHelpLine()
-    roof.divideLine()
+    // roof.drawHelpLine()
+    // roof.divideLine()
   }
 
   const drawRoofPolygon = (wall, offset = 50) => {
@@ -4465,6 +4271,7 @@ export function useMode() {
   }
 
   const createRoofRack = () => {
+    roof.divideLine()
     const trestlePolygons = canvas?.getObjects().filter((obj) => obj.name === 'trestle')
     // 이미 만들어진 가대가 있을 경우 return
     if (trestlePolygons.length !== 0) {
@@ -4475,7 +4282,6 @@ export function useMode() {
     canvas?.off('mouse:out')
     document.removeEventListener('keydown', handleKeyDown)
     const roofs = canvas?.getObjects().filter((obj) => obj.name === 'roof')
-    let roofCells = [] // roof에 적재된 cell들
     roofs.forEach((roof, index) => {
       const offsetPolygonPoint = offsetPolygon(roof.points, -20)
 
@@ -4498,8 +4304,6 @@ export function useMode() {
 
       canvas?.add(trestlePoly)
     })
-
-    setDrewRoofCells(roofCells)
   }
 
   //배터리 셀 넣기
@@ -4531,19 +4335,24 @@ export function useMode() {
 
       let drawRoofCells
       if (maxLengthLine.direction === 'right' || maxLengthLine.direction === 'left') {
-        drawRoofCells = trestle.fillCell({ width: 50, height: 100, padding: 0 })
+        drawRoofCells = trestle.fillCell({ width: 50, height: 100, padding: 10 })
         trestle.direction = 'south'
       } else {
-        drawRoofCells = trestle.fillCell({ width: 100, height: 50, padding: 0 })
+        drawRoofCells = trestle.fillCell({ width: 100, height: 50, padding: 10 })
         trestle.direction = 'east'
       }
 
       drawRoofCells.forEach((cell) => {
-        roofCells.push(cell)
+        drawCellsArray.push(cell)
       })
     })
 
-    setDrewRoofCells(roofCells)
+    setDrewRoofCells(drawCellsArray)
+  }
+
+  // 가대 방위 설정
+  const setDirectionTrestles = () => {
+    console.log('roof', roof)
   }
 
   const makeCellPowercon = () => {
@@ -4610,6 +4419,143 @@ export function useMode() {
     return { concaveIndices: concaveIndices, concavePointIndices: concavePointIndices }
   }
 
+  const drawHelpLineMode = () => {
+    if (!isObjectNotEmpty(roof)) {
+      alert('지붕을 먼저 그려주세요.')
+      setMode(Mode.DEFAULT)
+      return
+    }
+
+    const roofPoints = roof.points
+    const wallPoints = wall.points
+
+    roofPoints.forEach((roofPoint, index) => {
+      const circle = new fabric.Circle({
+        radius: 5,
+        fill: 'red',
+        left: roofPoint.x - 5,
+        top: roofPoint.y - 5,
+        selectable: true, // 선택 가능하게 설정
+        lockMovementX: true, // X 축 이동 잠금
+        lockMovementY: true, // Y 축 이동 잠금
+        lockRotation: true, // 회전 잠금
+        lockScalingX: true, // X 축 크기 조정 잠금
+        lockScalingY: true, // Y 축 크기 조정 잠금
+        name: 'helpPoint',
+      })
+
+      canvas?.add(circle)
+      canvas?.renderAll()
+    })
+  }
+
+  const cutHelpLines = () => {
+    // 먼저 hip을 자른다.
+    canvas
+      ?.getObjects()
+      .filter((obj) => obj.name === 'helpLine')
+      .forEach((line, index1) => {
+        canvas
+          ?.getObjects()
+          .filter((obj) => obj.name === 'helpLine')
+          .forEach((line2, index2) => {
+            if (line === line2) {
+              return
+            }
+
+            const intersectionPoint = calculateIntersection(line, line2)
+            if (!intersectionPoint) {
+              return
+            }
+
+            canvas?.remove(line)
+            canvas?.remove(line2)
+
+            const hip1 = new QLine([line.x1, line.y1, intersectionPoint.x, intersectionPoint.y], {
+              stroke: 'black',
+              strokeWidth: 1,
+              selectable: false,
+              name: 'hip',
+            })
+
+            const hip2 = new QLine([line2.x1, line2.y1, intersectionPoint.x, intersectionPoint.y], {
+              stroke: 'black',
+              strokeWidth: 1,
+              selectable: false,
+              name: 'hip',
+            })
+
+            const interSectionCircle = new fabric.Circle({
+              radius: 5,
+              fill: 'red',
+              left: intersectionPoint.x - 5,
+              top: intersectionPoint.y - 5,
+              selectable: true, // 선택 가능하게 설정
+              lockMovementX: true, // X 축 이동 잠금
+              lockMovementY: true, // Y 축 이동 잠금
+              lockRotation: true, // 회전 잠금
+              lockScalingX: true, // X 축 크기 조정 잠금
+              lockScalingY: true, // Y 축 크기 조정 잠금
+              name: 'helpPoint',
+            })
+
+            canvas?.add(hip1)
+            canvas?.add(hip2)
+            roof.innerLines.push(hip1)
+            roof.innerLines.push(hip2)
+            canvas?.add(interSectionCircle)
+            canvas?.renderAll()
+          })
+      })
+
+    canvas
+      ?.getObjects()
+      .filter((obj) => obj.name === 'helpLine')
+      .forEach((line) => {
+        const helpPoints = canvas?.getObjects().filter((obj) => obj.name === 'helpPoint')
+        let cnt = 0
+        let intersectionPoints = []
+        helpPoints.forEach((point) => {
+          if (cnt === 2) {
+            return
+          }
+          if (
+            turf.booleanPointOnLine(
+              turf.point([point.left + point.radius, point.top + point.radius]),
+              turf.lineString([
+                [line.x1, line.y1],
+                [line.x2, line.y2],
+              ]),
+            )
+          ) {
+            intersectionPoints.push(point)
+            cnt++
+          }
+        })
+
+        if (intersectionPoints.length === 2) {
+          const ridge = new QLine(
+            [
+              intersectionPoints[0].left + intersectionPoints[0].radius,
+              intersectionPoints[0].top + intersectionPoints[0].radius,
+              intersectionPoints[1].left + intersectionPoints[1].radius,
+              intersectionPoints[1].top + intersectionPoints[1].radius,
+            ],
+            {
+              stroke: 'black',
+              strokeWidth: 1,
+              selectable: false,
+              name: 'ridge',
+            },
+          )
+          roof.innerLines.push(ridge)
+          canvas?.add(ridge)
+          canvas?.remove(line)
+          canvas?.renderAll()
+        }
+      })
+  }
+
   return {
     mode,
     setMode,
@@ -4627,5 +4573,7 @@ export function useMode() {
     createRoofRack,
     drawRoofPolygon,
     drawCellInTrestle,
+    setDirectionTrestles,
+    cutHelpLines,
   }
 }
diff --git a/src/util/common-utils.js b/src/util/common-utils.js
new file mode 100644
index 00000000..9f53fede
--- /dev/null
+++ b/src/util/common-utils.js
@@ -0,0 +1,11 @@
+/**
+ * Check if an object is not empty.
+ * @param {Object} obj - The object to check.
+ * @returns {boolean} - Returns true if the object is not empty, false otherwise.
+ */
+export const isObjectNotEmpty = (obj) => {
+  if (!obj) {
+    return false
+  }
+  return Object.keys(obj).length > 0
+}
diff --git a/src/util/qpolygon-utils.js b/src/util/qpolygon-utils.js
index 5a216524..77af0df5 100644
--- a/src/util/qpolygon-utils.js
+++ b/src/util/qpolygon-utils.js
@@ -1127,7 +1127,7 @@ export const splitPolygonWithLines = (polygon) => {
     })
   })
 
-  roofs.forEach((roofPoint) => {
+  roofs.forEach((roofPoint, index) => {
     const roof = new QPolygon(roofPoint, {
       fontSize: polygon.fontSize,
       stroke: 'black',
@@ -1135,6 +1135,7 @@ export const splitPolygonWithLines = (polygon) => {
       strokeWidth: 3,
       name: 'roof',
       selectable: false,
+      startDirection: polygon.lines[index].direction,
     })
 
     polygon.canvas.add(roof)