In this tutorial you will learn to convert two convert two rectangles into an image using the Mesh tool in Adobe Illustrator CS3.
Create two rectangles having different colour.
Choose on rectangle and select the Mesh tool from the tools panel.
Lots of nodes will appear:
Select each node and move them until you reach the desired image.
This is the result I got by moving the nodes.
Do the same with the second triangle. You can copy and paste the first image and change its colour.
You can put two images together. You will get the following result.