Question

In the figure, a ball is thrown leftward from the left edge of the roof, at height h above the ground. The ball hits the ground 1.40 s later, at distance d = 23.0 m from the building and at angle θ = 59.0° with the horizontal. (a) Find h. (Hint: One way is to reverse the motion, as if on videotape.) What are the (b) magnitude and (c) angle relative to the horizontal of the velocity at which the ball is thrown (positive angle for above horizontal, negative for below)?

Answer 1

The answer guide says the angle is positive but the online accepted answer is a negative angle. I don't understand.

Answer 2

I have already solved the rest, its only the angle orientation that I am confused about.