diff --git a/examples/index.html b/examples/index.html
index 9be2637..b8a88e0 100644
--- a/examples/index.html
+++ b/examples/index.html
@@ -25,13 +25,14 @@
   var map = new maptalks.Map('map', {
     center: [108.93, 34.27],
     zoom: 5,
-    projection: 'EPSG:4326',
     baseLayer: new maptalks.TileLayer('base', {
       urlTemplate: 'https://webst01.is.autonavi.com/appmaptile?style=6&x={x}&y={y}&z={z}'
     })
   });
 
-  var layer = new maptalks.VectorLayer('vector').addTo(map);
+  var layer = new maptalks.VectorLayer('vector', {
+    enableSimplify : false
+  }).addTo(map);
 
   var drawTool = new MaptalksPlot.PlotDraw({
     mode: 'Curve'
diff --git a/src/geometry/Polygon/GatheringPlace.js b/src/geometry/Polygon/GatheringPlace.js
index 4a6f8dd..fe9d335 100644
--- a/src/geometry/Polygon/GatheringPlace.js
+++ b/src/geometry/Polygon/GatheringPlace.js
@@ -9,7 +9,6 @@ import * as Constants from '../../Constants'
 import {
   Mid,
   getThirdPoint,
-  MathDistance,
   getBisectorNormals,
   getCubicValue
 } from '../helper/index'
@@ -44,8 +43,9 @@ class GatheringPlace extends maptalks.Polygon {
     if (count < 2) return
     if (count === 2) {
       let mid = Mid(_points[0], _points[1])
-      let d = MathDistance(_points[0], mid) / 0.9
-      let pnt = getThirdPoint(_points[0], mid, Constants.HALF_PI, d, true)
+      const measurer = this._getMeasurer()
+      const distance = measurer.measureLength(Coordinate.toCoordinates(_points[0]), Coordinate.toCoordinates(mid)) / 0.9
+      let pnt = getThirdPoint(measurer, _points[0], mid, Constants.HALF_PI, distance, true)
       _points = [_points[0], pnt, _points[1]]
     }
     let mid = Mid(_points[0], _points[2])
diff --git a/src/geometry/Polygon/Lune.js b/src/geometry/Polygon/Lune.js
index f159d46..615070f 100644
--- a/src/geometry/Polygon/Lune.js
+++ b/src/geometry/Polygon/Lune.js
@@ -8,7 +8,6 @@ import * as Constants from '../../Constants'
 import {
   Mid,
   getThirdPoint,
-  MathDistance,
   isClockWise,
   getAzimuth,
   getArcPoints,
@@ -42,15 +41,18 @@ class Lune extends maptalks.Polygon {
     const count = this._points.length
     let _points = Coordinate.toNumberArrays(this._points)
     if (count < 2) return
+    const measurer = this._getMeasurer()
     if (count === 2) {
       let mid = Mid(_points[0], _points[1])
-      let d = MathDistance(_points[0], mid)
-      let pnt = getThirdPoint(_points[0], mid, Constants.HALF_PI, d)
+      let pnt = getThirdPoint(
+        measurer, _points[0], mid, Constants.HALF_PI,
+        measurer.measureLength(Coordinate.toCoordinates(_points[0]), Coordinate.toCoordinates(mid))
+      )
       _points.push(pnt)
     }
     let [pnt1, pnt2, pnt3, startAngle, endAngle] = [_points[0], _points[1], _points[2], undefined, undefined]
     let center = getCircleCenterOfThreePoints(pnt1, pnt2, pnt3)
-    let radius = MathDistance(pnt1, center)
+    let radius = measurer.measureLength(Coordinate.toCoordinates(pnt1), Coordinate.toCoordinates(center))
     let angle1 = getAzimuth(pnt1, center)
     let angle2 = getAzimuth(pnt2, center)
     if (isClockWise(pnt1, pnt2, pnt3)) {
@@ -60,7 +62,7 @@ class Lune extends maptalks.Polygon {
       startAngle = angle1
       endAngle = angle2
     }
-    _points = getArcPoints(center, radius, startAngle, endAngle)
+    _points = getArcPoints(measurer, center, radius, startAngle, endAngle)
     _points.push(_points[0])
     this.setCoordinates([
       Coordinate.toCoordinates(_points)
diff --git a/src/geometry/Polygon/Sector.js b/src/geometry/Polygon/Sector.js
index f0575a0..64ff143 100644
--- a/src/geometry/Polygon/Sector.js
+++ b/src/geometry/Polygon/Sector.js
@@ -6,7 +6,6 @@
 
 import * as maptalks from 'maptalks'
 import {
-  MathDistance,
   getAzimuth,
   getArcPoints
 } from '../helper/index'
@@ -43,10 +42,11 @@ class Sector extends maptalks.Polygon {
       this.setCoordinates([this._points])
     } else {
       let [center, pnt2, pnt3] = [_points[0], _points[1], _points[2]]
-      let radius = MathDistance(pnt2, center)
+      const measurer = this._getMeasurer()
+      const radius = measurer.measureLength(Coordinate.toCoordinates(pnt2), Coordinate.toCoordinates(center))
       let startAngle = getAzimuth(pnt2, center)
       let endAngle = getAzimuth(pnt3, center)
-      let pList = getArcPoints(center, radius, startAngle, endAngle)
+      let pList = getArcPoints(measurer, center, radius, startAngle, endAngle)
       pList.push(center, pList[0])
       this.setCoordinates([
         Coordinate.toCoordinates(pList)
diff --git a/src/geometry/helper/index.js b/src/geometry/helper/index.js
index b0d499e..490b58e 100644
--- a/src/geometry/helper/index.js
+++ b/src/geometry/helper/index.js
@@ -169,6 +169,7 @@ export const getCubicValue = (t, startPnt, cPnt1, cPnt2, endPnt) => {
 
 /**
  * 根据起止点和旋转方向求取第三个点
+ * @param measurer
  * @param startPnt
  * @param endPnt
  * @param angle
@@ -176,30 +177,40 @@ export const getCubicValue = (t, startPnt, cPnt1, cPnt2, endPnt) => {
  * @param clockWise
  * @returns {[*,*]}
  */
-export const getThirdPoint = (startPnt, endPnt, angle, distance, clockWise) => {
+export const getThirdPoint = (measurer, startPnt, endPnt, angle, distance, clockWise) => {
   let azimuth = getAzimuth(startPnt, endPnt)
   let alpha = clockWise ? (azimuth + angle) : (azimuth - angle)
   let dx = distance * Math.cos(alpha)
   let dy = distance * Math.sin(alpha)
-  return ([endPnt[0] + dx, endPnt[1] + dy])
+  const vertex = measurer.locate({
+    'x': endPnt[0],
+    'y': endPnt[1]
+  }, dx, dy)
+  return [vertex['x'], vertex['y']]
 }
 
 /**
  * 插值弓形线段点
+ * @param measurer
  * @param center
  * @param radius
  * @param startAngle
  * @param endAngle
+ * @param numberOfPoints
  * @returns {null}
  */
-export const getArcPoints = (center, radius, startAngle, endAngle) => {
-  let [x, y, points, angleDiff] = [null, null, [], (endAngle - startAngle)]
+export const getArcPoints = (measurer, center, radius, startAngle, endAngle, numberOfPoints = 100) => {
+  let [dx, dy, points, angleDiff] = [null, null, [], (endAngle - startAngle)]
   angleDiff = ((angleDiff < 0) ? (angleDiff + (Math.PI * 2)) : angleDiff)
-  for (let i = 0; i < 200; i++) {
-    const angle = startAngle + angleDiff * i / 200
-    x = center[0] + radius * Math.cos(angle)
-    y = center[1] + radius * Math.sin(angle)
-    points.push([x, y])
+  for (let i = 0; i < numberOfPoints; i++) {
+    const rad = angleDiff * i / numberOfPoints + startAngle
+    dx = radius * Math.cos(rad)
+    dy = radius * Math.sin(rad)
+    const vertex = measurer.locate({
+      'x': center[0],
+      'y': center[1]
+    }, dx, dy)
+    points.push([vertex['x'], vertex['y']])
   }
   return points
 }