



 
Hi Jamie. Use the law of cosines: c^{2} = a^{2} + b^{2}  2abCos(C) This lets you calculate c. Then you can use the other form to find A: You will need to use inverse cosine (arc cos) to solve for angle A. To find B, you could use the law of cosines again, as you did to find A, but a shortcut is to recall that the three angles of any triangle add up to 180 degrees, so it would be faster just to subtract: B = 180  A  C. Cheers,  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 