The two triangles are similar. They both share a common angle and the smaller one is inside the larger one. For instance two triangles of the same angle degrees intwine. The small triangle has sides of 3 and 5. The large triangle has sides of 8 and an unknown number we should call "z". Our job is to find out what "z" is.
8/3 = z/5
8/3 = 2.6
2.6 * 5 = 13.3
