# Exterior Angles of Polygons

### The Exterior Angle is the angle between any side of a shape,

and a line extended from the next side.

Note: when you add up the Interior Angle and Exterior Angle you get a straight line, 180°. (See Supplementary Angles)

## Polygons

A Polygon is any flat shape with straight sides

The Exterior Angles of a Polygon add up to 360° |
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In other words the exterior angles add up to
Note: This rule only works for simple polygons |

Here is another way to think about it: Each lines changes direction until you eventually get back to the start: |