Question

Suppose a triangle has sides a, b, and c with side c the longest side, and that a^2 + b^2 > c^2. Let x be the measure of the angle opposite the side of length c. Which of the following must be true? Check all that apply.

A. x is an acute angle.
B. The triangle is not a right triangle.
C. The triangle in question is a right triangle.
D. cosx < 0