How can ratios of lengths of sides within right triangles help determine other lengths and angle measures in the triangles?

Solve the equation using the zero-product property. -3n(7n - 5) = 0 a. 0, -5/7 b. -1/3, -5/7 c. -1/3, 5/7 d. 0, 5/7

Abird on top of a 200 ft bridge tower sees a man standing on the lower part of the bridge (which is 50 ft above the ground). the angle of depression from the bird is 26 ̊. how far is the man from the base of the bridge tower? with explanation and pictures .

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a