Menu: Draw / Ellipse / Arc 
Creates an elliptical arc by defining the major and minor axes.
- Click the endpoints of the major axis, or enter the major axis length and angle in the Inspector Bar.
- Set the length of the minor axis, which is always perpendicular to the major axis. You can also enter the axis length in the Inspector Bar.
- 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. You can also enter the included angle.
Local menu options:
Center: 
Enables you to define the major axis from the center.
Rotation: 
Enables you to define the minor axis at an angle from the major axis.