congruent triangle are the only triangles that can be used to show why the slope is the same between any two points on a non vertical line. True or false? HELP PLEASE ASAP

In the diagram, the ratios of two pairs of corresponding sides are equal to prove that almn - axyz by the sas similarity theorem, it also needs to be shown that x 6 z un z zz un = 2x zləzz lezy