diff --git a/web/app/arc.js b/web/app/arc.js
new file mode 100644
index 00000000..7520de51
--- /dev/null
+++ b/web/app/arc.js
@@ -0,0 +1,106 @@
+
+TCAD.TWO.Arc = function(a, b, c) {
+  TCAD.TWO.SketchObject.call(this);
+  this.a = a;
+  this.b = b;
+  this.c = c;
+  a.parent = this;
+  b.parent = this;
+  c.parent = this;
+};
+
+TCAD.TWO.utils.extend(TCAD.TWO.Arc, TCAD.TWO.SketchObject);
+
+TCAD.TWO.Arc.prototype._class = 'TCAD.TWO.Arc';
+
+TCAD.TWO.Arc.prototype.collectParams = function(params) {
+  this.a.collectParams(params);
+  this.b.collectParams(params);
+  this.c.collectParams(params);
+};
+
+TCAD.TWO.Arc.prototype.draw = function(ctx, scale) {
+  TCAD.TWO.SketchObject.prototype.draw.call(this, ctx, scale);
+  this.a.draw(ctx, scale);
+  this.b.draw(ctx, scale);
+  this.c.draw(ctx, scale);
+};
+
+TCAD.TWO.Arc.prototype.getReferencePoint = function() {
+  return this.c;
+};
+
+TCAD.TWO.Arc.prototype.translateImpl = function(dx, dy) {
+  this.a.translate(dx, dy);
+  this.b.translate(dx, dy);
+  this.c.translate(dx, dy);
+};
+
+TCAD.TWO.Arc.prototype.drawImpl = function(ctx, scale) {
+  ctx.beginPath();
+  var r = TCAD.math.distance(this.a.x, this.a.y, this.c.x, this.c.y);
+  ctx.arc(this.c.x, this.c.y, r,
+    Math.atan2(this.a.y - this.c.y, this.a.x - this.c.x),
+    Math.atan2(this.b.y - this.c.y, this.b.x - this.c.x));
+  ctx.stroke();
+};
+
+
+TCAD.TWO.AddArcTool = function(viewer, layer) {
+  this.viewer = viewer;
+  this.layer = layer;
+  this.arc = null;
+  this.point = null;
+  this._v = new TCAD.Vector(0, 0, 0);
+};
+
+TCAD.TWO.AddArcTool.prototype.mousemove = function(e) {
+  if (this.point != null) {
+    var p = this.viewer.screenToModel(e);
+    this.point.x = p.x;
+    this.point.y = p.y;
+
+    var r = TCAD.math.distance(this.arc.a.x, this.arc.a.y, this.arc.c.x, this.arc.c.y);
+    if (this.point.id === this.arc.b.id) {
+      //force placement second point on the arc
+      var v = this._v;
+      v.set(this.arc.b.x - this.arc.c.x, this.arc.b.y - this.arc.c.y, 0);
+      v._normalize()._multiply(r);
+      this.arc.b.x = v.x + this.arc.c.x;
+      this.arc.b.y = v.y + this.arc.c.y;
+    } else {
+      var ang = Math.atan2(this.point.y - this.arc.c.y, this.point.x - this.arc.c.x) + (2 * Math.PI -  0.3);
+      
+      ang %= 2 * Math.PI; 
+      
+      this.arc.b.x = this.arc.c.x + r * Math.cos(ang);
+      this.arc.b.y = this.arc.c.y + r * Math.sin(ang);
+    }
+
+    this.viewer.refresh();
+  }
+};
+
+TCAD.TWO.AddArcTool.prototype.mouseup = function(e) {
+  if (this.arc == null) {
+    var p = this.viewer.screenToModel(e);
+    this.arc = new TCAD.TWO.Arc(
+      new TCAD.TWO.EndPoint(p.x, p.y),
+      new TCAD.TWO.EndPoint(p.x, p.y),
+      new TCAD.TWO.EndPoint(p.x, p.y)
+    );
+    this.point = this.arc.a;
+    this.layer.objects.push(this.arc);
+    this.viewer.refresh();
+  } else if (this.point.id === this.arc.a.id) {
+    this.point = this.arc.b;
+  } else {
+    this.viewer.toolManager.releaseControl();
+  }
+};
+
+TCAD.TWO.AddArcTool.prototype.mousedown = function(e) {
+};
+
+TCAD.TWO.AddArcTool.prototype.mousewheel = function(e) {
+};
diff --git a/web/app/canvas.js b/web/app/canvas.js
index 02f8abd0..b9afdee9 100644
--- a/web/app/canvas.js
+++ b/web/app/canvas.js
@@ -398,54 +398,6 @@ TCAD.TWO.Segment.prototype.drawImpl = function(ctx, scale) {
   ctx.stroke();
 };
 
-
-TCAD.TWO.Arc = function(a, b, c) {
-  TCAD.TWO.SketchObject.call(this);
-  this.a = a;
-  this.b = b;
-  this.c = c;
-  a.parent = this;
-  b.parent = this;
-  c.parent = this;
-};
-
-TCAD.TWO.utils.extend(TCAD.TWO.Arc, TCAD.TWO.SketchObject);
-
-TCAD.TWO.Arc.prototype._class = 'TCAD.TWO.Arc';
-
-TCAD.TWO.Arc.prototype.collectParams = function(params) {
-  this.a.collectParams(params);
-  this.b.collectParams(params);
-  this.c.collectParams(params);
-};
-
-TCAD.TWO.Arc.prototype.draw = function(ctx, scale) {
-  TCAD.TWO.SketchObject.prototype.draw.call(this, ctx, scale);
-  this.a.draw(ctx, scale);
-  this.b.draw(ctx, scale);
-  this.c.draw(ctx, scale);
-};
-
-TCAD.TWO.Arc.prototype.getReferencePoint = function() {
-  return this.c;
-};
-
-TCAD.TWO.Arc.prototype.translateImpl = function(dx, dy) {
-  this.a.translate(dx, dy);
-  this.b.translate(dx, dy);
-  this.c.translate(dx, dy);
-};
-
-TCAD.TWO.Arc.prototype.drawImpl = function(ctx, scale) {
-  ctx.beginPath();
-  ctx.moveTo(this.a.x, this.a.y);
-  ctx.lineTo(this.b.x, this.b.y);
-
-//  ctx.arc(c.x, c.y, ,0,2*Math.PI);
-  ctx.stroke();
-};
-
-
 TCAD.TWO.Point = function(x, y, rad) {
   this.x = x;
   this.y = y;
diff --git a/web/app/main2d.js b/web/app/main2d.js
index 32c00808..bc5ef006 100644
--- a/web/app/main2d.js
+++ b/web/app/main2d.js
@@ -39,6 +39,10 @@ TCAD.App2D = function() {
       app.viewer.toolManager.takeControl(new TCAD.TWO.AddSegmentTool(app.viewer, layer));
     },
 
+    addArc : function () {
+      app.viewer.toolManager.takeControl(new TCAD.TWO.AddArcTool(app.viewer, layer));
+    },
+
     pan : function() {
       app.viewer.toolManager.releaseControl();
     },
@@ -91,6 +95,7 @@ TCAD.App2D = function() {
 
   };
   actionsF.add(actions, 'addSegment');
+  actionsF.add(actions, 'addArc');
   actionsF.add(actions, 'pan');
   actionsF.add(actions, 'save');
   actionsF.add(actions, 'coincident');
diff --git a/web/app/math/math.js b/web/app/math/math.js
new file mode 100644
index 00000000..3bbee53e
--- /dev/null
+++ b/web/app/math/math.js
@@ -0,0 +1,7 @@
+TCAD.math = {};
+
+TCAD.math.distance = function(x1, y1, x2, y2) {
+  var dx = x1 - x2;
+  var dy = y1 - y2;
+  return Math.sqrt(dx * dx + dy * dy);
+}
\ No newline at end of file
diff --git a/web/app/vector.js b/web/app/vector.js
index 3df7eac4..600e4092 100644
--- a/web/app/vector.js
+++ b/web/app/vector.js
@@ -27,8 +27,12 @@ TCAD.Vector.prototype.setV = function(data) {
   return this;
 };
 
-TCAD.Vector.prototype.multiply = function(factor) {
-  return new TCAD.Vector(this.x * factor, this.y * factor, this.z * factor);
+TCAD.Vector.prototype.multiply = function(scalar) {
+  return new TCAD.Vector(this.x * scalar, this.y * scalar, this.z * scalar);
+};
+
+TCAD.Vector.prototype._multiply = function(scalar) {
+  return this.set(this.x * scalar, this.y * scalar, this.z * scalar);
 };
 
 TCAD.Vector.prototype.dot = function(vector) {
@@ -59,6 +63,15 @@ TCAD.Vector.prototype.normalize = function() {
   return new TCAD.Vector(this.x / mag, this.y / mag, this.z / mag);
 };
 
+
+TCAD.Vector.prototype._normalize = function() {
+  var mag = this.length();
+  if (mag == 0.0) {
+    return this.set(0, 0, 0)
+  }
+  return this.set(this.x / mag, this.y / mag, this.z / mag)
+};
+
 TCAD.Vector.prototype.cross = function(a) {
   return new TCAD.Vector(
       this.y * a.z - this.z * a.y,
diff --git a/web/canvas.html b/web/canvas.html
index eaedb361..908d508a 100644
--- a/web/canvas.html
+++ b/web/canvas.html
@@ -12,6 +12,8 @@
   <script src="lib/three/three.js"></script>
   <script src="lib/dat.gui.min.js"></script>
   <script src="app/canvas.js"></script>
+  <script src="app/arc.js"></script>
+  <script src="app/math/math.js"></script>
 
   <script src="app/math/lm.js"></script>
   <script src="app/constr/constraints.js"></script>