ΔGHI is similar to ΔKLM. If the ratio of Perimeter of ΔGHI:Perimeter of ΔKLM=4:9 and the length of GH is 8cm, what is the length of the corresponding side KL?

For similar triangles, the ratio of their perimeters is equal to the ratio of their corresponding sides.
Perimeter of ΔKLM
Perimeter of ΔGHI
​
=
KL
GH
​

9
4
​
=
KL
8
​

4×KL=8×9
KL=
4
72
​
=18cm