**Interior angles** describe the sum of angles found within a given shape. To solve interior angle problems, you need to memorize the interior angles of two shapes: the triangle and the circle.

- A triangle has an interior angle of 180 degrees.

- A circle has an interior angle of 360 degrees.

The interior angles of any other polygon can be derived from these two shapes.

*Example*

What is the interior angle of the following shape?

**Solution**

While at first glance this may seem complex, any polygon with sharp corners can be divided into triangles.

The hexagon has now been divided into 6 triangles. Since we know each triangle has an interior angle of 180 degrees. 6 multiplied by 180 is 1080. The answer is 1080 degrees.

Click here for access to the best GMAT Study Guide & GMAT Practice Exams