ANSWER:
Given: In Δ ABC, ∠ A = 50° and ∠ B = 60°
In Δ ABC,
∠ A + ∠ B + ∠ C = 180°
⇒50° + 60° + ∠ C = 180°
⇒110° + ∠ C = 180°
⇒∠ C = 180° - 110°
⇒∠ C = 70°
(Angle sum property of a triangle)
Hence, the longest side will be opposite to the largest angle (∠ C = 70°) i.e. AB.And, the shortest side will be opposite to the smallest angle (∠ A = 50° ) i.e. BC.