In order to work out the size of missing interior angles in polygons, it is important to know what the interior angles add up to: The interior angles of a triangle sum to 180°. The interior ...

It’s possible to work out the angles of polygons with more than 4 sides by cutting them up into triangles. This is a regular hexagon. It has 6 sides and it can be divided into 4 triangles, like ...

Often we can also use the other properties of a shape to work out more missing angles. Use the fact that parallelograms have two pairs of equal angles to calculate the missing angles in this question.

The sum of the angles inside any polygon can be found by spitting the polygon into triangles.

Learn about and revise angles, lines and multi-sided shapes and their properties with this BBC Bitesize GCSE Maths Eduqas study guide.

Learn how to measure interior and exterior angles in polygons with this BBC Bitesize Maths article. For students between the ages of 11 and 14.