Choose a shape and drag its vertices. Area is always measured in square units.

Turn on Decompose to split the polygon into triangles. The pieces add up to the area of the whole shape: the composing and decomposing strategy.

Because vertices sit on grid points, any horizontal or vertical side has a length you can read from its coordinates. For example, the side from (−2, 3) to (5, 3) is 7 units long.