a rectangle is 7 ft by 9ft. a second is similar to the first with a perimeter of 260 ft. what are the dimensions of the second rectangle?

1 answer

if the new one is similar to the old one, then it must be
7x by 9x
and its perimeter would be 2(7x+9x) or 32x

so 32x = 260
x = 8.125

so the new one is 7(8.125) by 9(8.125)
or
56.875 by 73.125

check : 73.125/56.875 = 73125/56875 = 2925/2275 = 9/7 --- ratio works

perimeter = 2(56.875) + 2(73.125) = 260 --- checks!