​ Triangle ABC ​ is similar to triangle DEF ​ . The length of AC¯¯¯¯¯ is 12 cm. The length of ​EF¯¯¯¯¯​ is 15 cm. The length of DF¯¯¯¯¯ is 9 cm. What is the length of ​BC¯¯¯¯¯​ ? Enter your answer in the box. ____cm

Answer:
BC = 20 cm

Explanation:
We are given that:
triangle ABC is similar to triangle DEF
Therefore, the similarity ratio can be written as follows:
AB/DE = BC/EF = AC/DF
We are given that:
AC = 12 cm
EF = 15 cm
DF = 9 cm
and we want to find the length of BC

We will substitute with the givens in the above relation to get BC as follows:
BC/EF = AC/DF
BC/15 = 12/9
9BC = 15*12
9BC = 180
BC = 180/9
BC = 20 cm

Hope this helps :)