Question
If $\cos ^{2} A+\cos ^{2} B+\cos ^{2} C=1$, prove that the triangle is right angled.
Step 1
Step 1: Rewrite the given equation $\cos ^{2} A+\cos ^{2} B+\cos ^{2} C=1$ as $\cos ^{2} A = 1 - \cos ^{2} B - \cos ^{2} C$. Show more…
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