3. (4 pts) A person standing 400 ft from the base of a mountain measures the angle of elevation from the ground to the top of the mountain to be 25. The person then walks 500 ft straight back and measures the angle of elevation to now be 20. How tall is the mountain? (Note that the base of the mountain is NOT directly underneath its top.) 4. (4 pts) A conveyor belt is driven by a wheel with a diameter of 20 cm. If the belt needs to move along steadily at a rate of 200 cm/min, how fast should the wheel rotate in revolutions per minute