The angles of elevation of the top of a tower from two points at a distance of 4 m and 9 m from the base of the tower and in the same straight line with it are complementary. The height of the tower is
I am facing north. I turn left and walk 30 m. Then I turn right and walk 20 m, then I turn left and walk 10 m and then turning right and walk 50 m. Then I turn left and walk 50 m. In which direction am I from the starting point?