This is a computer version of Tangram. Tangram is an ancient Chinese puzzle with just a few geometric shapes (to be exact, one square, one parallelogram and five triangles of varied sizes). Move and rotate these pieces to build a goal shape (squares, polygons, profiles,... ). The program has dozens of pre-made goals, but you can create and save your own. If you are stuck, the program can help you by placing a piece of your choice in the correct position.