Hollow Oval Tool
The Hollow Oval tool allows you to draw empty ovals.
To use this tool...
After selecting the colours you will be using to draw the oval, click on the Hollow Oval button. Point the crosshairs of the cursor at the corner of an imaginary rectangle having the same length and width of the desired oval. Hold down the left mouse button to draw with the foreground colour; hold down the right mouse button to draw with the background colour. Drag the cursor to the opposite corner of the oval and release the mouse button.