Monica's rectangular living room is 12ft by 15ft. She has a square rug that covers 5/9 of the floor. What is the side length of the square rug?

A rectangle's area is just the product of its base times its height. (A = bh) In this case, the area of her room's floor is 12 * 15 = 180 ft².

5/9 of 180 ft² is 100 ft².

A square IS a rectangle, so we can find the area with A=bh ... but since all of the sides are the same length, we would just use A=s². Let's use what we know to solve for s.

A = s²

100 = s²

√100 = s

10 = s