Step-by-step explanation:
We have to know that in order to solve for the volume of a rectangular prism, we have to use this formula: l * w * h. This stands for length multiplied by width multiplied by height.
<u>Step 1</u>
Let's look at the numbers we already have. The height of the prism is 4 feet and the width is 5 feet. When we multiply them together, we got 20 feet.
<u>Step 2</u>
The volume of this prism adds up to 150 square feet. To find the length of this prism, we have to divide 150 by 20.

Our final answer: l = 7.5 feet
We can check our answer by multiplying all the numbers together.
4 * 5* 7.5 = 150
Sec∅ = 1/cos∅
= 1/cos(240)
= 1/cos(180 + 60)
= 1/-cos(60)
= 1/(-1/2)
= -2
1.7088061E11 on a calculator that's what I did