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If ∠A and ∠B are acute angles such that cos A = cos B, then show that ∠A = ∠B. |
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Answer» In a right angled triangle ABC, cos A = \(\frac{AC}{AB}\) and cos B = \(\frac{BC}{AB}\) ∵ cos A = cos B \(\frac{AC}{AB}\) = \(\frac{BC}{AB}\) ∴ AC = BC We have, opposite sides of equal angles are equal. Therefore, In a right angled triangle ABC ∠A = ∠B = 45° |
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