If ∠ A and∠ B are acute angles such that tanA = tanB then prove that ∠ A = ∠ B.
Consider ΔABC to be a right - angled triangle.
∴ tanA = BC/AC
tanB = AC/BC
Given that tanA = tanB
BC/AC = AC/BC
BC2 = AC2
→ BC = AC
→ ∠ A = ∠ B (In a triangle, angles opposite to equal angles are equal)