Square with a "radius" of 11m
The "radius" is the distance from the center of the square to any vertex
The area is 4(1/2)11^2 = 2 * 121 = 242 m^2
Pentagon with a side of 9m
The pentagon will be composed of 5 congruent triangles
The height of each is given by (9/2)/tan (36°)
So...the total area is
5 (1/2)(9)(9/2)/tan(36°) = (5)(9/2)^2/tan(36°) ≈ 139.4 m^2
Pentagon with a radius of 5m
We have 5 congruent triangles with sides of 5 and an included angle of 72° between these sides
The area = 5 (1/2) (5)^2sin (72°) ≈ 59.4m^2
Hexagon with a side of 12 yd
We have six congruent equilateral triangles...each side = 12 yd
The area is 6(1/2)(12)^2* √3/2 ≈ 216√3 yds^2 ≈ 374.1 yds^2