Question

We have enough material to build a fence around a station that has a perimeter of 180 feet. The width of the rectangular space must be 30 1/4 feet. What must the length be?

Answer 1

To solve this problem you must use the formula of the perimeter (P) of a rectangle and clear the length (L). The perimeter of a rectangle, is:

P=2L+2W

"P" is the perimeter of the rectangle (P=180 feet).
"L" is the lenght of the rectangle.
"W" is the widht of the rectangle (W=30 1/4 feet=30.25 feet).

As you can see, you already have the value of the perimeter (P) and the value of the widht (W). Now, you can clear the lenght (L):

P=2L+2W
2L=P-2W
L=(P-2W)/2

When you substitute the values, you obtain:

L=(P-2W)/2
L=(180 feet-2x30.25 feet)/2
L=(119.5 feet)/2
L=59.75 feet

What must the length be?

The answer is: 59.75 feet