Q31 of 35 Page 288

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)


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