Posted by Milly on .
There are two similar triangles XYZ, and ABC. If x = 12 and z = 3c, find a. How do I work with that problem when z = 3c?

Algebra 
Brooke,
Similar are proportional.
12 is to a as 3c is to c
cross product 12c = 3ac
divide both sides by 3c and a = 4