If you where to simplify 4/6 you will get an equivalent fraction. So you would find a common numeral between the tw0. In this case it would be 2. So it would be 2/3 cause you would divide each number by two to get 2/3.
The two triangles will be similar (same shape, and each side of one triangle the same multiple of the corresponding side of the other triangle), but not necessarily the same size.
The key word here is "similar;" be sure you understand what that means in trig.
