The ratio of two sides of a parallelogram is 3:4. If its perimeter is 56cm, what are the lengths of the sides?

1 Answer
Dec 21, 2015

#12,"16 cm"#

Explanation:

If the two sides have a ratio of #3:4#, that means their sides can be represented as #3x# and #4x#, which also have a ratio of #3:4#.

Thus, if the sides of a parallelogram are #3x# and #4x#, its perimeter is equal to the following expression:

#P=2(3x)+2(4x)#

The perimeter is #56#.

#56=2(3x)+2(4x)#

Divide both sides by #2#.

#28=3x+4x#

#28=7x#

#x=4#

Plug these back into our side lengths: #3x# and #4x#

#3(4)="12 cm"#

#4(4)="16 cm"#