Perimeter of a Rectangle

Problem 1:
Find the perimeter of a rectangle with a length of 12 and width of 5.
Solution:
The length and width are given to us. Let’s plug the given dimensions into the formula.
P = 2(l + w) = 2(12 + 5)
P = 2(17) = 34
The perimeter of the rectangle is 34.

Problem 2:
A rectangle has a perimeter of 15 and a length of 5. What is the width?
Solution:
Let’s plug the given dimensions into the formula, then isolate w to find the width.
P = 2(l + w) → 15 = 2(5 + w)
15 = 10 + 2w
5 = 2w
w = 2.5
The width of the rectangle is 2.5.