Question

Suppose a triangle has sides a, b, and c, and let θ be the angle opposite the side of length a. If cosθ > 0, what must be true?


1) b^2 + c^2 < a^2

2) a^2 + b^2 = c^2

3) a^2 + b^2 > c^2

4) b^2 + c^2 > a^2


I chose answer choice 4 but idk if it's right