b) The shape is a regular heptagon, so all the angles must be equal. The shape has 5 sides and can be split into 3 triangles. The sum of the angles is \(3 \times 180 = 540^{\circ}\). To find the ...

A regular heptagon or septagon is inscribed within a circle. The greatest distance d from the circumference to the perimeter is 12.31229 cm. Find the area A of the heptagon or septagon.