Menu: Draw / Ellipse / Elliptical Arc, Fixed Ratio 
Creates an elliptical arc by specifying its aspect ratio - the ratio of the major axis to the minor axis. The axes of the ellipse are orthogonal.
- Enter the aspect ratio in the a:b ratio field on the Inspector Bar. (If you want to repeat this value later then lock it, otherwise the field reverts back to the default.)
- Select the centerpoint of the ellipse.
- Move the mouse to size the ellipse.
- A dotted line appears from the centerpoint. Move the cursor to set the arc start angle, or enter the angle in the Inspector Bar.
- Move the cursor counterclockwise to draw the arc, or enter the end angle or arc length in the Inspector Bar.
