A rectangular football pitch has its length equal to twice its width and a perimeter of 360m. Find i

A rectangular football pitch has its length equal to twice its width and a perimeter of 360m. Find its length and width.

The area of a rectangle (A) is:
A = lw --> where l is the length and w is the width

We're given l = 2w, so we substitute this into the Area equation:
A = (2w)w
A = 2w^2

We're given the area of the pitch is 360, so we set:
2w^2 = 360

We type this equation into our search engine, follow the links, and get:
w = 6*sqrt(5)

Now we take this, and substitute it into this equation:
6*sqrt(5)l = 360

Dividing each side by 6*sqrt(5), we get:
l = 60/sqrt(5)