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:
![(AP)/(OP)=tan(11.25^(\circ))](https://img.qammunity.org/2019/formulas/mathematics/high-school/2swckirxcsslxg26pgmqom9338d3gacpql.png)
![\therefore OP=(AP)/(tan(11.25^(\circ)))=(2)/(tan(11.25^(\circ)))\approx10.1](https://img.qammunity.org/2019/formulas/mathematics/high-school/o9o0ut6jheyocj07pxvhuikk57o1l3hh4r.png)
Thus the area of one triangle is
![(1)/(2)* 4* 10.1=20.2](https://img.qammunity.org/2019/formulas/mathematics/high-school/33czlhj663h75exd7s079597m79lsi2kdm.png)
Therefore, the area of all the 16 triangles that make up the regular polygon is:
![16* 20.2=323.2](https://img.qammunity.org/2019/formulas/mathematics/high-school/dym4qkhgsuidr9su2kj5q4qvrq7j1vx8ck.png)
Thus the area of the polygon is 323.2 squared inches.