Brilliant replaces lecture videos with hands-on, interactive lessons. It’s a better (and more fun) way to learn.

We've seen that area is something we can calculate for any shape, but it doesn't tell us much about the shape itself. For example, a hexagon with one unit of area can be regular, with all sides the same length, or it could be highly irregular with no single side-length equal to any other.

In this lesson, we’ll learn to describe shapes by their angles, and we'll discover a property that is fundamental to all polygons.

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