Answer:
Area of nonagon = 1044.6 square millimetres.
Explanation:
Let side of the nonagon is a
Given:
The perimeter of nonagon is 117 millimetres

Put the perimeter value in above equation


So the side of the nonagon is 13
The area of the nonagon is .

where a is side of the nonagon.
Put value of side in above equation





Therefore, the area of the nonagon is 1044.6 square millimetre.