To start off, the equation you want to use the formula V=whl
Next, you simply plug in the values you already know, so you have 450=w*20*7.5
After you do that you multiply 20 times 7.5 to get which is 150, which leaves you with 450= w *150 to solve for w, you need to isolate it. To do that you divide 450 by 150. You are left with the answer of 3.
Note that you have a right triangle here, with hypotenuse 13 ft, and base 5 ft. Using the Pythagorean Theorem, we find the height of the upper tip of the ladder as follows:
(13 ft)^2 = y^2 + (5 ft)^2. Then y^2 = 144 ft^2, and y =height= 12 ft
