The side lengths of three triangles are shown in the table. Which of the triangles is a right triangle?

Explain how you can use the associative property to evaluate (7x50)x4.

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 .

Ihonestly have no clue if it's each or none.