What is the length of the sides of an octagon given a 16' diameter?

Divide into 8 triangles from the central point. One central angle = 1/8 x 360 = 450

create a right triangle with a perpendicular to the center of one side, the angle is now 22.50. the radius is 16/2 = 8

using trig: sin 22.50 = y/8

y = 8(sin 22.50 ) = 3.06 feet (remember this is half of one side)

one side = 6.12 feet