To draw a 3-point elliptical arc

1. Click the Ellipse Tool in the toolbox.

2. Click the 3-Point Arc button in the ribbon.

3. Drag the arc's diameter and release the mouse button.

4. Move the pointer to create the arc.

5. Click the left mouse button to draw the arc.

Use the Proportional Constraint button to force Designer to draw radial arcs that are one-quarter of a perfect circle. Use the Reverse Direction button to control the bowing direction of the arc. When the button is not selected (the default), the arc bows to the right as you draw upward and left as you draw downward. The opposite occurs when the button is selected.