Let ABC be a triangle with, ∠A = ∠B = ∠C.
Considering, ∠A = ∠B
We get, BC = AC (Sides opposite to equal angles are equal.)
Considering, ∠B = ∠C
We get, AB = BC (Sides opposite to equal angles are equal.)
∴ AB = BC = AC.
Hence, proved that every equiangular triangle is equilateral.
