use the law of cosines to find the side of each triangle. round the answer to nearest tenth.
angle(A ) = 58 degree
side (b) = 9
side (c) =12
find side (a) ?
use the law of cosines. its pretty straight forward. Usually when you learn the law of cosines you learn that
c^2 = a^2 + b^2 - 2ab cos C. You use this form if you have angle C. If you have angle A, which is what your question is asking, you use:
a^2 = b^2 + c^2 - 2bc cos A
and if you are given angle B then you use:
b^2 = a^2 +c^2 - 2ac cos B