I got this question wrong and I'm hoping someone can explain to me where I went wrong. In a triangle... angle A = 350 side b = 7 cm side c = 3 cm I need to find side a which is the side opposite angle A. The formaula to use is -a2 = b2 + c2 - 2bc cos A so, with the figures plugged in that comes out as... a2 = 72 + 32 - 2 x 3 x 7 cos 35 which comes to... a2 = 58 - 42 cos 35 SO FAR, I KNOW THAT IS CORRECT. I seem to have made the mistake at this point. I multiplied 16 (58-42) by cos 35 and took the square root of the answer, which gave me 3.62 cm. However, apparently the right answer is 4.86 cm. What did I do wrong?