Effective students of geometry should be able to identify ... If you know the sum of all angles with common vertex, for instance, this will make calculating adjacent angles much easier.

The bed has four corners which we've labelled vertex a, b, c and d. If you count along the squares from each corner you'll see that each vertex has moved 3 squares to the right. If we translate ...

An exterior angle is the angle made with the side of the shape, if you were to extend the side of the shape in one direction at each vertex. Find the interior angles of the shape below.