Formula for face diagonal?

What is the lcm of 16 and 40 ? 24 and 40 ?

Me. i can't figure out this question. give an explanation too. .

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