Question

A circular rug has a radius of 2.5 feet. You want to sew fringe border around the rug. Do you need to know the circumference or area?

Answer 1

So you want to sew a fringe border which means that what you need to know is how long it has to be. This means you must find the circumference of the rug. The circumference of a circle is given by:

$2\cdot\pi\cdot r$

Where r is the radius. In this case the circumference is:

$2\cdot\pi\cdot2.5=15.7$