diff --git a/src/util/qpolygon-utils.js b/src/util/qpolygon-utils.js
index 4ed06608..47a923a3 100644
--- a/src/util/qpolygon-utils.js
+++ b/src/util/qpolygon-utils.js
@@ -712,7 +712,7 @@ export const drawShedRoof = (roofId, canvas) => {
 
 export const drawRidgeRoof = (roofId, canvas) => {
   const roof = canvas?.getObjects().find((object) => object.id === roofId)
-  const hasNonParallelLines = roof.lines.filter((line) => line.x1 !== line.x2 && line.y1 !== line.y2)
+  const hasNonParallelLines = roof.lines.filter((line) => Math.abs(line.x1 - line.x2) > 1 && Math.abs(line.y1 - line.y2) > 1)
   if (hasNonParallelLines.length > 0) {
     alert('대각선이 존재합니다.')
     return
@@ -721,6 +721,7 @@ export const drawRidgeRoof = (roofId, canvas) => {
   drawHips(roof, canvas)
   connectLinePoint(roof, canvas)
   modifyRidge(roof, canvas)
+  drawCenterLine(roof, canvas)
 }
 
 /**
@@ -1532,7 +1533,8 @@ const changeEavesRoof = (currentRoof, canvas) => {
           line.name !== LINE_TYPE.SUBLINE.RIDGE &&
           line.name !== LINE_TYPE.SUBLINE.HIP &&
           line.name !== LINE_TYPE.SUBLINE.VALLEY &&
-          line.name !== OUTER_LINE_TYPE.OUTER_LINE,
+          line.name !== OUTER_LINE_TYPE.OUTER_LINE &&
+          line.name !== 'wallLine',
       )
       .forEach((line) => {
         roof.innerLines = roof.innerLines.filter((l) => l.id !== line.id)
@@ -1704,7 +1706,8 @@ const changeGableRoof = (currentRoof, canvas) => {
           line.name !== LINE_TYPE.SUBLINE.RIDGE &&
           line.name !== LINE_TYPE.SUBLINE.HIP &&
           line.name !== LINE_TYPE.SUBLINE.VALLEY &&
-          line.name !== OUTER_LINE_TYPE.OUTER_LINE,
+          line.name !== OUTER_LINE_TYPE.OUTER_LINE &&
+          line.name !== 'wallLine',
       )
       .forEach((line) => {
         roof.innerLines = roof.innerLines.filter((l) => l.id !== line.id)
@@ -1890,7 +1893,8 @@ const changeHipAndGableRoof = (currentRoof, canvas) => {
             line.name !== LINE_TYPE.SUBLINE.RIDGE &&
             line.name !== LINE_TYPE.SUBLINE.HIP &&
             line.name !== LINE_TYPE.SUBLINE.VALLEY &&
-            line.name !== OUTER_LINE_TYPE.OUTER_LINE,
+            line.name !== OUTER_LINE_TYPE.OUTER_LINE &&
+            line.name !== 'wallLine',
         )
         .forEach((line) => {
           roof.innerLines = roof.innerLines.filter((l) => l.id !== line.id)
@@ -2127,7 +2131,8 @@ const changeJerkInHeadRoof = (currentRoof, canvas) => {
             line.name !== LINE_TYPE.SUBLINE.RIDGE &&
             line.name !== LINE_TYPE.SUBLINE.HIP &&
             line.name !== LINE_TYPE.SUBLINE.VALLEY &&
-            line.name !== OUTER_LINE_TYPE.OUTER_LINE,
+            line.name !== OUTER_LINE_TYPE.OUTER_LINE &&
+            line.name !== 'wallLine',
         )
         .forEach((line) => {
           roof.innerLines = roof.innerLines.filter((l) => l.id !== line.id)
@@ -2407,7 +2412,8 @@ const changeWallRoof = (currentRoof, canvas) => {
         line.name !== LINE_TYPE.SUBLINE.RIDGE &&
         line.name !== LINE_TYPE.SUBLINE.HIP &&
         line.name !== LINE_TYPE.SUBLINE.VALLEY &&
-        line.name !== OUTER_LINE_TYPE.OUTER_LINE,
+        line.name !== OUTER_LINE_TYPE.OUTER_LINE &&
+        line.name !== 'wallLine',
     )
     .forEach((line) => {
       roof.innerLines = roof.innerLines.filter((l) => l.id !== line.id)
@@ -2702,6 +2708,187 @@ const reDrawPolygon = (polygon, canvas) => {
   return newPolygon
 }
 
+const drawCenterLine = (roof, canvas) => {
+  const roofLines = roof.lines
+  roofLines.forEach((currentRoof) => {
+    const hips = roof.innerLines.filter(
+      (line) => (currentRoof.x1 === line.x1 && currentRoof.y1 === line.y1) || (currentRoof.x2 === line.x1 && currentRoof.y2 === line.y1),
+    )
+    const ridge = roof.innerLines
+      .filter((line) => line.name === LINE_TYPE.SUBLINE.RIDGE)
+      .filter((line) => {
+        if (currentRoof.x1 === currentRoof.x2) {
+          if (line.x1 === line.x2) {
+            return line
+          }
+        } else {
+          if (line.y1 === line.y2) {
+            return line
+          }
+        }
+      })
+      .reduce((prev, current) => {
+        let currentDistance, prevDistance
+        if (Math.sign(currentRoof.x1 - currentRoof.x2) === 0) {
+          currentDistance = Math.abs(currentRoof.y1 - current.y1)
+          prevDistance = prev ? Math.abs(currentRoof.y1 - prev.y1) : Infinity
+        } else {
+          currentDistance = Math.abs(currentRoof.y1 - current.y2)
+          prevDistance = prev ? Math.abs(currentRoof.y1 - current.y2) : Infinity
+        }
+        return prevDistance < currentDistance ? prev : current
+      }, null)
+    let points = []
+    if (hips.length === 2 && Math.abs(hips[0].x2 - hips[1].x2) < 1 && Math.abs(hips[0].y2 - hips[1].y2) < 1) {
+      // console.log('삼각')
+      const x1 = (currentRoof.x1 + currentRoof.x2) / 2
+      const y1 = (currentRoof.y1 + currentRoof.y2) / 2
+      points.push(x1, y1, hips[0].x2, hips[0].y2)
+    } else {
+      // console.log('삼각 아님')
+      if (
+        ((ridge.x1 === hips[0].x2 && ridge.y1 === hips[0].y2) || (ridge.x2 === hips[0].x2 && ridge.y2 === hips[0].y2)) &&
+        ((ridge.x1 === hips[1].x2 && ridge.y1 === hips[1].y2) || (ridge.x2 === hips[1].x2 && ridge.y2 === hips[1].y2))
+      ) {
+        //사각이면 마루와 현재 라인 사이에 길이를 구한다
+        // console.log('사각')
+        if (Math.sign(currentRoof.x1 - currentRoof.x2) === 0) {
+          const yPoints = [currentRoof.y1, currentRoof.y2, ridge.y1, ridge.y2].sort((a, b) => a - b)
+          const x1 = (currentRoof.x1 + currentRoof.x2) / 2
+          const x2 = (ridge.x1 + ridge.x2) / 2
+          const y = (yPoints[1] + yPoints[2]) / 2
+          if (
+            ((currentRoof.y1 <= y && y <= currentRoof.y2) || (currentRoof.y2 <= y && y <= currentRoof.y1)) &&
+            ((ridge.y1 <= y && y <= ridge.y2) || (ridge.y2 <= y && y <= ridge.y1))
+          ) {
+            points.push(x1, y, x2, y)
+          }
+        } else {
+          const xPoints = [currentRoof.x1, currentRoof.x2, ridge.x1, ridge.x2].sort((a, b) => a - b)
+          const y1 = (currentRoof.y1 + currentRoof.y2) / 2
+          const y2 = (ridge.y1 + ridge.y2) / 2
+          const x = (xPoints[1] + xPoints[2]) / 2
+          if (
+            ((currentRoof.x1 <= x && x <= currentRoof.x2) || (currentRoof.x2 <= x && x <= currentRoof.x1)) &&
+            ((ridge.x1 <= x && x <= ridge.x2) || (ridge.x2 <= x && x <= ridge.x1))
+          ) {
+            points.push(x, y1, x, y2)
+          }
+        }
+      } else {
+        //사각 아님
+        if (Math.sign(currentRoof.x1 - currentRoof.x2) === 0) {
+          let xPoints = []
+          xPoints.push(ridge?.x1, ridge?.x2)
+          hips.forEach((hip) => {
+            xPoints.push(hip.x2)
+          })
+          let maxPoint = xPoints.reduce((prev, current) => {
+            const currentDistance = Math.abs(currentRoof.x1 - current)
+            const prevDistance = prev ? Math.abs(currentRoof.x1 - prev) : 0
+            return prevDistance > currentDistance ? prev : current
+          }, null)
+
+          xPoints = xPoints.filter((point) => point === maxPoint)
+
+          let oppositeLine
+          if (xPoints.length === 1) {
+            if (ridge?.x1 === xPoints[0] || ridge?.x2 === xPoints[0]) {
+              oppositeLine = ridge
+            }
+            if (oppositeLine === undefined) {
+              oppositeLine = hips.find((hip) => hip.x2 === xPoints[0])
+            }
+            points.push(currentRoof.x1, oppositeLine.y2, oppositeLine.x2, oppositeLine.y2)
+          } else if (xPoints.length > 1) {
+            xPoints = [...new Set(xPoints)] // 중복제거
+            if (ridge.length > 0) {
+              let boolX1 = xPoints.some((x) => x === ridge.x1)
+              let boolX2 = xPoints.some((x) => x === ridge.x2)
+              if (boolX1 && boolX2) {
+                oppositeLine = ridge
+              }
+              if (oppositeLine) {
+                const sortPoints = [currentRoof.y1, currentRoof.y2, oppositeLine.y1, oppositeLine.y2].sort((a, b) => a - b)
+                const y = (sortPoints[1] + sortPoints[2]) / 2
+                if (
+                  ((currentRoof.y1 <= y && y <= currentRoof.y2) || (currentRoof.y2 <= y && y <= currentRoof.y1)) &&
+                  ((oppositeLine.y1 <= y && y <= oppositeLine.y2) || (oppositeLine.y2 <= y && y <= oppositeLine.y1))
+                ) {
+                  points.push(currentRoof.x1, y, oppositeLine.x1, y)
+                }
+              }
+            }
+          }
+        } else {
+          let yPoints = []
+          yPoints.push(ridge?.y1, ridge?.y2)
+          hips.forEach((hip) => {
+            yPoints.push(hip.y2)
+          })
+          const maxPoint = yPoints.reduce((prev, current) => {
+            const currentDistance = Math.abs(currentRoof.y1 - current)
+            const prevDistance = prev ? Math.abs(currentRoof.y1 - prev) : 0
+            return prevDistance > currentDistance ? prev : current
+          })
+          yPoints = yPoints.filter((y) => y === maxPoint)
+
+          let oppositeLine
+          if (yPoints.length === 1) {
+            if (ridge?.y1 === yPoints[0] || ridge?.y2 === yPoints[0]) {
+              oppositeLine = ridge
+            }
+            if (oppositeLine === undefined) {
+              oppositeLine = hips.find((hip) => hip.y2 === yPoints[0])
+            }
+            points.push(oppositeLine.x2, currentRoof.y1, oppositeLine.x2, oppositeLine.y2)
+          } else if (yPoints.length > 1) {
+            let boolY1 = yPoints.some((y) => y === ridge.y1)
+            let boolY2 = yPoints.some((y) => y === ridge.y2)
+            if (boolY1 && boolY2) {
+              oppositeLine = ridge
+            }
+            if (oppositeLine) {
+              const sortPoints = [currentRoof.x1, currentRoof.x2, oppositeLine.x1, oppositeLine.x2].sort((a, b) => a - b)
+              const x = (sortPoints[1] + sortPoints[2]) / 2
+              if (
+                ((currentRoof.x1 <= x && x <= currentRoof.x2) || (currentRoof.x2 <= x && x <= currentRoof.x1)) &&
+                ((oppositeLine.x1 <= x && x <= oppositeLine.x2) || (oppositeLine.x2 <= x && x <= oppositeLine.x1))
+              ) {
+                points.push(x, currentRoof.y1, x, oppositeLine.y1)
+              }
+            }
+          }
+        }
+      }
+    }
+    if (points !== null) {
+      const pitchSizeLine = new QLine(points, {
+        stroke: '#000000',
+        strokeWidth: 2,
+        strokeDashArray: [5, 5],
+        selectable: false,
+        fontSize: roof.fontSize,
+        attributes: {
+          roofId: roof.id,
+          type: 'pitchSizeLine',
+        },
+      })
+      canvas.add(pitchSizeLine)
+      canvas.renderAll()
+
+      const adjust = Math.sqrt(
+        Math.pow(Math.round(Math.abs(pitchSizeLine.x1 - pitchSizeLine.x2) * 10), 2) +
+          Math.pow(Math.round(Math.abs(pitchSizeLine.y1 - pitchSizeLine.y2) * 10), 2),
+      )
+      const currentDegree = currentRoof.attributes.pitch > 0 ? getDegreeByChon(currentRoof.attributes.pitch) : currentRoof.attributes.degree
+      const height = Math.tan(currentDegree * (Math.PI / 180)) * adjust
+      const lengthText = Math.round(Math.sqrt(Math.pow(adjust, 2) + Math.pow(height, 2)))
+      pitchSizeLine.setLengthText(lengthText)
+    }
+  })
+}
+
 function createRoofMarginPolygon(polygon, lines, arcSegments = 0) {
   const offsetEdges = []