Question

Can somebody please help me with this.!

Answer 1

an easier way to do this is to look at the number of sides (9) and subtract it by 2 (7). Then you can just multiply that number by 180
this works for every polygon

Answer 2

1260

Explanation:

First you will need to find the amount of sides of the polygon:

(After looking it is 9)

Each angle of the side of a nonagon is 140 degrees.

Multiply by 9 since you can make 9 triangles:

140 x 9 = 1260