We’re at the Polygons annual party. It’s polygons only so to get a ticket, you have to be a 2D shape, with straight sides. Polygons can be grouped based the number of sides they have. So let ...

A short video showing how to prove the sum of the angles in a n-sided polygon is 180° × (n-2). For example a hexagon has 6 sides, so (n-2) is 4, and the internal angles add up to 180° × 4 = 720°.