The 2D ellipse is used for annotating round and elliptical objects in camera images, for example wheels or road markings. It is available when your task includes an ellipse class — select it in the Create tabCreate tab and draw with the Ellipse tool.
An ellipse is placed with three clicks:
Click the bottom center point.
Click the top center point.
The first two clicks define the height and the tilt of the ellipse.
Click either the left-most or right-most point on the line.
This sets the width, and the ellipse is created.
Select the ellipse to show its control points: