Answer:
3420°
Step-by-step explanation:
The sum of angle measures of an n-gon is ...
angle total = (n-2)×180°
For n = 21, the angle total is ...
21-gon total = (21 -2)×180° = 3420°
Multiply both sides by 8
5/8g × 8 = 40× 8
5g = 320
Divide both sides by 5
5g/5 = 320/5
G = 64
Formula
Area = L*w
Hint : To find the area of a rectangle , multiply the length times the width
I hope that's help !
Hope this helps at all. :)
I believe the answer is C. 40 and 140.
