Answer:
Step-by-step explanation:
Look at the picture.
We have the triangle 30° - 60° - 90°. The sides are in ratio 1 : √3 : 2.
We have:
<em>divide both sides by √3</em>
It's a right triangle.
f(4) = 15 * 1.4^4 = 57.624 inches²
Remember SOH/CAH/TOA. We will use SOH, which means of the angle is equal to the opposite side over the hypotenuse.