Write an equation pls help!! it’s my exam

Marie drew the triangle shown. she wants to draw a second triangle that is different from this one. use the drop-down menus below to complete the statements about the second triangle.

Monica build a remote control toy airplane for science project to test the plane she launched it from the top of a building the plane travel a horizontal distance of 50 feet before landing on the ground a quadratic function which models the height of the plane in feet relative to the ground at a horizontal distance of x feet from the building is shown

In the figure shown below, m < 40 and ab =8. which equation could be used to find x?