Aregular 15-gon has a perimeter of 150 m. to the nearest tenth, what is the area of the figure?

In the problem, it was being highlighted that the polygon is a 15-gon which means it is a Pentadecagon which has a formula for the area shown below:
A=15a²/8 (√3 + √15 + √2 √(5+√5))
A=15a²/8 (9.409)
where a is the side measurement of the polygon
To get value, we use the given perimeter such as
Perimeter=15a
150=15a
a=10m

Solving for the area:
Area=15a²/8 *(9.409)
=(15*(10²)/8) *(9.409)
Area = 1,764.19 m²

The volume is 56.8 triangular the