Hi.
I have a math exam tomorrow .What I ask you is this: Both the law of sines and the law of cosines apply to any triangles, but for right angles triangles they don't add any useful information. In the diagram if the angle opposite a is a right angle then, since the cosine of 90^{o} is zero, the law of cosines says that a^{2} = b^{2} + c^{2} Also the sine of 90^{o} is 1 so the law of sines for this triangle says Penny
