Given,

∆ABC and ∆EDF,

→ AB/DE = BC/FD

By converse of basic proportionality theorem, that if a line divides any two sides of a triangle in the same ratio, then the line must be parallel to the third side.

As we have,

∆ABC ∼ ∆EDF

Then,

∠B = ∠D,

∠A = ∠E and,

∠C = ∠F