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Practical Practice

1. Let's use our formula to confirm that the sum of interior angles in a hexagon is 720 degrees!

Remember, the formula for the sum of the interior angles of a polygon is , where is the number of sides of a polygon Since we have a hexagon, we know that there are 6 sides, and so the sum of the interior angles of a hexagon can be found by

(6)

2. Here's a dodecagon (dough-deck-uh-gon)! It has 12 sides. Find the sum of the interior angles of a dodecagon!

What should the sum of the interior angles of a dodecagon be?

Remember that the formula we discovered was , where is the number of sides of the polygon

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This may look like a circle, but it is in fact a 65-gon! (That's a lot of sides!) After a certain point, we stop giving special names to polygons and just name them by how many sides they have.

Find the sum of the interior angles of a 65-gon!

You may need to bust out a calculator for this one

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