perplexus.info :: Just Math : trigonometry and a triangle

trigonometry and a triangle (Posted on 2004-02-26)

Prove that in a triangle ABC,:

sin(A)sin(B)sin(C) + cos(A)cos(B) = 1

implies:

A = B = 45° and C = 90°.

See The Solution Submitted by mohan

Rating: 2.7143 (7 votes)

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trigonomentry and a triangle

| Comment 11 of 15 |

Sin A * sin A = 0.5
0.5 *Sin C = 0.5 * 1 = 0.5 + cos A/B * cos A/B = 0.5
0.5 + 0.5 = 1

Posted by liam on 2004-03-13 11:18:40

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