For a better understanding of the solution please find the diagram in the attached file.
The diagram is that of a triangular part of the regular polygon. The triangle
is an isosceles triangle because the sides OA and OB are equal. Now, The angle
. This is because the angle around the central angle of a polygon is 360 degrees in total.
Now, because
is an isosceles triangle, angle OAP will be half of angle OAB. Thus,
.
AP will be half of AB. Therefore, AP=2.
Now, the apothem, OP can thus be found as:
Thus the area of one triangle is
Therefore, the area of all the 16 triangles that make up the regular polygon is:
Thus the area of the polygon is 323.2 squared inches.