### Home > CCG > Chapter 8 > Lesson 8.2.2 > Problem8-84

8-84.

Always a romantic, Marris decided to bake his girlfriend a cookie in the shape of a regular dodecagon ($12$-gon) for Valentine’s Day.

1. If the edge of the dodecagon is $6$ cm, what is the area of the top of the cookie?

Try splitting the cookie into triangles.
What information do you already know about these triangles' angles and sides?
Can you use this to find the area of a single triangle?

2. His girlfriend decides to divide the cookie into $12$ congruent pieces. After $9$ of the pieces have been eaten, what area of the cookie is left?

Multiply the area of a single triangle by the number of triangles remaining after some have been eaten.