I don't know how to do it. But can you figure it out of this question?

2. Two triangles are similar if the only difference is size. That is, all corresponding angles are equal and all corresponding sides are in proportion (have the same ratio). Consider the below triangles: R Q N 3 6 7 Y P a) Notice that ZP = ZX, 2Q = ZY, and LR = ZZ. If A PQR is similar to A XYZ, the following equation holds: PQ QR RP XY YZ ZX Where PQ corresponds to XY, QR corresponds to YZ, and RP corresponds to ZX. Find the scale factor (the common ratio). b) Given the scale factor, find the length of side ZX