Question

One of the angles of a triangle is 110°, the two other angles are equal. Find their value.

Answer 1

Let in Δ ABC,

∠A = 110° and ∠B = ∠C

But ∠A + ∠B + ∠C = 180°

⇒ 110° + ∠B + ∠B = 180°

⇒ 2 ∠B = 180° - 110°

⇒ 2 ∠B = 70°

⇒ ∠B = `70^circ/2 = 35^circ`

∴ ∠C = ∠B = 35°

Hence each of two equal angles is 35°