Adding A Corner Anchor Point

How to add a corner anchor point to a oval using the selection tool:

• In the tool bar click on the "Sub-selection Tool" icon.
• On the stage left click on the curve to highlight the points.
• Hover over a the perimeter line, when the cursor turns into an arrow with a curve next to it.
• Hold down the the "Alt" key and the left mouse button then drag out the new point.