Question

a triangle has sides a, b, and c, and the angle opposite the side of length a is obtuse what must be true?
a. a^2 + b^2 < c^2
b. a^2 + c^2 a^2

Answer 1

you may use cosine law :
\[a^2 = b^2+c^2-2bc\cos(A)\]

Answer 2

so how do i find the answer