What is the ratio in simplest form of 68:84

The volume of a cube-shaped shipping container is 13,824 cubic inches. find the edge length of the shipping container.

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

The anwser cause i do not understand just plez