10. angle APB = (1/2) arc AB
108 = (1/2) arc AB
multiply both sides by 2 to clear the fraction
216 = arc AB
11. Area of regular Octagon s = 5 in
A = (P * apothem)/2 => => If you divide the octagon into 8 triangles, the apothem is the perpendicular height of the triangle.
A = (5 * 8 * 6)/2
A = 120 in^2
Area of regular Hexagon s = 5 in
A = (5 * 6 * 4.3)/2
A = 129 in^2