Question

For a particular rectangle, twice the width is 4 meters shorter than the length. The area of the rectangle is 126 square meters. What is the perimeter of the rectangle? ? meters

Answer 1

Let l be the length of the rectangle and w its width.

Then its area is given by:

a = l*w

Its perimeter is given by:

p = 2l + 2w

We also know that, for this specific triangle, we have:

2w = l - 4

l = 2w + 4

a = 126 m²

Applying this result in the area formula, we have:

w*l = 126

w(2w + 4) = 126

2w² +4w = 126

2w + 4w - 126 = 0

Therefore, w = 7 m and l = 2*7 + 4 = 10 m

Then, the perimeter is given by:

p = 2*18 + 2*7 = 36 + 14 = 50 m