Construction Ellipse Bi-tangent to Circle, Tangent to Line

1. Call the Ellipse command.

2. Select a construction circle for the ellipse to be bi-tangent to. The center of the ellipse will coincide with the center of the circle. The length of the ellipse's first semi-axis will be equal to the radius of the circle. The orientation of the ellipse will depend on the second semi-axis, which is defined on the next step. A circle may be selected in one of the following ways:

•Move the cursor over the desired circle, using object snappings, and press or <Enter>.

•Activate the following automenu option:

If the option is activated via keyboard, then the construction circle nearest to cursor gets selected instantly.
If the option is activated via mouse, then you have to additionally press within drawing window for selecting the nearest circle.

3. Select a straight construction line for the ellipse to be tangent to. The second semi-axis of the ellipse will be limited by the selected line and oriented normally to it. A line may be selected in one of the following ways:

•Move the cursor over the desired line, using object snappings, and press or <Enter>.

•Activate the following automenu option:

If the option is activated via keyboard, then the line nearest to cursor gets selected instantly.
If the option is activated via mouse, then you have to additionally press within drawing window for selecting the nearest line.

After creating an ellipse the command returns to the initial state.