Please answer number 20 with work!

A

x/64 = 36/36

this is the answer

C

Step-by-step explanation:

when doing proportions you have to align your fractions accordingly.

we are putting x over 64 which means that small triangle in the top and big triangle in the bottom. On the other side its going to be 36 because of the small triangle's side and in the bottom we put the big triangle's side which will be 72 because 36+36=72