Question

What is the sum of the interior angles of a dodecagon?

Answer 1

Exterior is 360/12

Answer 2

\[180(n - 2) \implies \text{n sides} \\ 180(12 - 2) \implies \text{12 sides}\]

Answer 3

Or you could use the fact that the sum of exterior angles is 360 degrees, and compute the exterior angle.

Answer 4

Note that the exterior angle you have computed is in the case of a regular dodecagon.

Answer 5

Still, you can subtract the exterior angle from 180 and multiply that my 12.