The hexagon divides the circle into 6 parts. That means the angle projecting each side is: 360°÷ 6 = 60°
The area of a circle is: πr²
78.54 in² divided by pi is 25 making the radius = 5
I would then use SOH CAH TOA to solve for the side.. knowing the hypotenuse is the radius and the angle to split it into a right triangle is 30°
Sin(30) = s/5
5*Sin(30) = s
12*s = perimeter hexagon
(remember s is half the hexagon side)
12*5*Sin(30) = perimeter hexagon
30 inches = perimeter
