Question

The perimeter of a rectangle is 40 inches. if its length is three times its width, find the dimensions.'

Answer 1

The perimeter of a rectangle could be determined using
$\boxed{p = 2(l+w)}$

From the question above, we could draw informations
p = 40 inches
l = 3w

plug in the info to the perimeter formula
p = 2(l + w)
40 = 2(3w + w)
40 = 2(4w)
40 = 8w
w = 40/8
w = 5

l = 3w
l = 3(5)
l = 15

The dimension:
l = 15 in
w = 5 in