Question

what is the area of pentagon​

Answer 1

Answer:

1 method:

Area of a regular pentagon = pa/2, where, p = the perimeter and a = the apothem.

If you don't know the perimeter, calculate it from the side length: p = 5s, where s is the side length.

2 method:

If you only know the side length, use the following formula:

Area of a regular pentagon = (5s2) / (4tan(36º)), where s = side length.

tan(36º) = √(5-2√5). So if your calculator doesn't have a "tan" function, use the formula Area = (5s2) / (4√(5-2√5)).