A rectangle has a perimeter of 37 inches. The lengths of its sides are multiplied by 9 to make a new rectangle. What is the perimeter of the new rectangle?

333 inches

Step-by-step explanation:

The perimeter of a rectangle is found using the formula P = 2l+2w where l is the length and w is the width. Lets say for example, the length is 5 and the width is 2. Then the perimeter will be P = 2*5+2*2 = 10 + 4 = 14. If each side is multiplied by 9 then the length is 5*9 = 45 and the width is 2*9 = 18. So the perimeter is P = 2*45 + 2*18 = 90 + 36 = 126.

Did you notice that 14 * 9 = 126? The perimeter is scaled up with the sides by the same number. So if the perimeter is 37 then scaled up it is 37*9 = 333.