You made the choice to choose the letter A, a second time.
<span>a=7b+8c+9d-10
a = 8c + 16d - 10
solve for c then
8c = a - 16d + 10
c = (</span>a - 16d + 10) / 8
or
c = a/8 - 2d + 5/4
If you multiply by 100 you will get the percentage
The correct answer is Choice B: 53.0 feet.
If you draw a picture of the cross section, you will have a right triangle. The hypotenuse is 58 and one of the legs is 23.6. All you have to do is use the Pythagorean Theorem and solve for the missing side.
x^2 + 23.6^2 = 58^2
