Area of the octagon = 8 * side length^2 / [4 * tan (180/8)] Area of the octagon = 8 * 9^2 / [4 * tan(22.5)] Area of the octagon = 648 / 4 * 0.41421 Area of the octagon = 648 /
<span>
<span>
<span>
1.65684
</span>
</span>
</span>
Area of the octagon =
<span>
<span>
<span>
391.1059607446
</span>
</span>
</span>
square inches
Gray Area = <span>
<span>
<span>
391.105 minus square area </span></span></span><span>Gray Area = 391.105 -81 </span>Gray Area = <span><span>310.105
square inches
