The Pen blocks and the Motion blocks are utilized in this project, but of special interest are a couple blocks from the Events group. A very useful block is the When this sprite clicked block. Even more useful and even more frequently used are the broadcast and When I receive blocks. Study the code in the example. Don't worry about the Control blocks. This project can be successfully completed without them, although it is a little nicer with them.

Alter the sample project in the following ways:

1. Instead of an equilateral triangle and a square, you will draw an equilateral pentagon, an equilateral hexagon, and an equilateral octagon. Each will require its own button.
2. Additionally, you will create a button called "CLEAR" which clears the screen. The other buttons will not clear the screen.
3. Make sure that spacing of all elements is even and that the hexagon, octagon, and pentagon are all about the same height.