Question

In Fig. 87, the corresponding arms of ∠ABC and ∠DEF are parallel. If ∠ABC = 75°, find ∠DEF.

Answer 1

Construction: Let G be the point of intersection of lines BC and DE.

∵ AB || DE and BC || EF

∴ $\angle \mathrm{ABC}=\angle \mathrm{DGC}=\angle \mathrm{DEF}=75°$ (Corresponding angles)​