Question

A rectangle and a square have the same area. The length of the rectangle is seventy feet more than two times its width. The length of a side of the square is thirty feet. What equation would help you solve for the dimensions of the rectangle? What are the dimensions of the rectangle?

Answer 1

Using the side of the square find the area:

Area = 30^2 = 900 square feet.

The rectangles area is the same, 900 square feet.

Let the width = X

The length would be 2X + 70

Area = length x width

X * 2x+ 70 = 900

This expands to 2x^2 * 70x = 900

Use the quadratic formula to solve for x:

-70 +/- sqrt(70^2-4*2(-900))/2*2

X = 10

Width = x = 10 feet

Length = 2x + 70 = 90 feet