A compound shape is shape made up of two or more basic shapes. You can place a thin rectangle horizontally on top of a thin rectangle placed vertically so that you form a T shape. Or, you can create an L shape by placing two thin rectangles perpendicular at right angles to each other, with one rectangle vertical and the other rectangle horizontal. You can combine any number of basic shapes to make a compound shape. The area of the compound shape equals the areas of its component shapes added together.

The basic shapes of geometry are squares, rectangles, circles and triangles, as well as trapezoids, rhombuses, stars, hexagons, octagons and ovals. You can use any of these shapes -- or sections of these shapes -- to construct a compound shape. You can have a compound shape that consists of a semi-circle attached to the side of a rectangle. You can also use multiple sections of basic shapes in the same compound shape. For example, you can make a heart shape out of a square and two semi-circles. Place the square on its vertice so that it resembles a diamond. To complete the heart shape, place one semi-circle along the top left side of the square -- with the semi-circle's flat side next to the top left side of the square -- and one semi-circle along the top right side of the square -- with its flat side next to the top right side of the square.