An elliptical arc is a portion of an ellipse. The default method for drawing an elliptical arc is to specify the endpoints of one axis of the ellipse, and then specify a distance representing half the length of the second axis. Then you specify the start and end angles for the arc, measured from the center of the ellipse in relation to its major axis. You can draw elliptical arcs using any of the following methods:
• AxisAxis ()
• AxisRotation ()
• CenterAxes ()
• CenterRotation ()
To draw an elliptical arc by specifying the axis endpoints
1 Do one of the following to choose Elliptical Arc AxisAxis ():
• On the ribbon, choose Home > Elliptical Arc AxisAxis or choose Draw > Elliptical Arc AxisAxis.
• On the menu, choose Draw > Elliptical Arc > Elliptical Arc AxisAxis.
• On the Draw toolbar, click the Elliptical Arc AxisAxis tool.
• Type ellipse and then press Enter, and then type a (for Arc) and press Enter.
2 Specify the first endpoint.
3 Specify the second endpoint.
4 Specify the halflength of the other axis.
5 Specify the start angle of the arc.
6 Specify the end angle.
CADdirect draws elliptical arcs in the direction you specify.
Go to Tools > Drawing Settings > Drawing Units tab. Click the Angular Units tab. The default setting is counterclockwise.

First axis endpoint (A), second axis endpoint (B), halflength of other axis (C), start angle of arc (D), and end angle (E).
