Suppose that you need to get a heavy couch into the bed of a pickup truck. (Part A figure) You know the bed of the truck is at a height of 1.00 \rm m and you need a ramp that makes an angle of 40^\circ with the ground if you are to be able to push the couch.
Use the sine function to determine how long of a board you need to use to make a ramp that just reaches the 1.00-\rm m high truck bed at a 40^\circ angle to the ground.