It is the sum of the lengths of the nine sides of the nonagon.
90
You add together the lengths of the nine sides of the nonagon.
nonagon
A regular nonagon has 9 sides and so its perimeter is 9*40 = 36 units of measurement
The answer depends on what information you have. If you have the length of a side, then the perimeter is nine times that length.
Add the length of all nine sides up.
189 feet.
40
It is: 162/9 = 18cm
396 ft
The area is 1583 square units, approx.