Use Donut to create closed shapes from two concentric circles. Each circle is made of four vertices.

Example of donut
(the middle mouse button) or scroll the mouse wheel. To orbit the viewport, hold down
and drag with
or scroll the mouse wheel. To create a donut:
The second circle can be larger or smaller than the first.
Most spline-based shapes share these parameters. For details, see Rendering rollout and Interpolation rollout.
The Donut shape offers the standard creation-method choice: Center or Edge. For details, see Creation Method rollout.
Creates a Donut spline from the keyboard. Use the X/Y/Z settings to specify the center point and the remaining parameters to specify the radii, then click Create. After creating the spline, you can use the Parameters rollout controls to adjust the settings (see following).

Once you have created a donut, you can make changes using the following parameters:
The radius of the first circle.
The radius of the second circle.