(real pls, geometry) in the diagram, the ratios of two pairs of corresponding sides are equal.

to prove that △lmn ~ △xyz by the sas similarity theorem, it also needs to be shown that

∠n ≅ ∠z

∠n ≅ ∠x

∠l ≅ ∠z

∠l ≅ ∠y

SAS similarity
two triangles are similar when they have corresponding angles that are congruent and corresponding sides with identical ratios.
According to our case, the ratios of two pairs of corresponding sides are
MN / NL = YZ / ZX, and the corresponding angles are ∠N ≅ ∠Z