To Create an Arc in Style
1. Click 
Style > > 
Arc. The Arc tab opens.
Style > > Arc. The Arc tab opens.2. Select the type of arc to create:
◦ 
Free Curve—Creates an arc that can be moved freely and is not constrained by any geometric entity.
Free Curve—Creates an arc that can be moved freely and is not constrained by any geometric entity.◦ 
Planar Curve—Creates an arc that lies on the specified plane. By default, the active plane is the reference plane.
Planar Curve—Creates an arc that lies on the specified plane. By default, the active plane is the reference plane.3. Click anywhere in the graphics window to place the center of the arc.
4. To change the reference plane, click the Plane or Reference collector on the References tab, and select a new reference plane.
5. To change the radius, type a value in the 
Radius box, or drag the handle on the arc.
Radius box, or drag the handle on the arc.6. To set the start and end location of the arc, type an angle value in the Start and End boxes, or drag the handles on the arc ends.
7. To move the arc, drag the center of the arc.
8. To maintain the curve shape during edits by moving the free points in proportion to the soft points, click the Options tab, and select the Proportional Update check box.
 | A curve without proportional update only changes shape at the soft point during edits. |
9. Click 
OK.
OK.