Consider the figure:
If BC = AC, x = 2y, and angle ACB = 60o, then find the value of ∠A + ∠B + ∠x + ∠y (in degrees).
∠C = 60o and BC = AC,
By angle sum property of triangle, ∠A = ∠B = 60o
∠A +∠B +∠x +∠y = 60∘ +60∘ +120∘ = 240∘
Since, ∠x +∠y = ∠A +∠B