Answer:
A = P * a / 2
A = 81.25
Step-by-step explanation:
We have that there is a corresponding formula for a regular decagon, which depends on the apothem and the perimeter, it is the following:
A = P * a / 2
In this case, the perimeter is the sum of all the sides, that is, 10 sides, therefore:
P = 10 * 3.25
P = 32.5 meters
We replace:
A = 32.5 * 5/2
A = 81.25
Which means that for that regular decagon, the area is 81.25 square meters.
