You can create ellipse by several construction types. Click View, Geom Curve to toggle the display of individual curve.
To create a ellipse:
Click Ellipse (Curve toolbar) or click Geometry, Curve, Ellipse.
In the dialog , select the type of you want to create the ellipse:
Parameters. Create an ellipse by center, normal, major and minor radius. You can also sketch ellipse when "Sketch on Plane" is checked.
Point/Axis. Create an ellipse by select a center point, an axis and define the major and minor radius.
Coordinate System . Create an ellipse by select a coordinate system, and define the major and minor radius.