In ΔABC, ∠A = 50° and ∠B = 60°.

Given: In ΔABC, ∠A = 50° and ∠B = 60°

In ΔABC,
∠A + ∠B + ∠C = 180°           (Angle sum property of a triangle)
⇒">⇒⇒50° + 60° + ∠C = 180°
⇒">⇒⇒110° + ∠C = 180°
⇒">⇒⇒∠C = 180° -">−- 110°
⇒">⇒⇒∠C = 70°

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.