Question

A lighthouse is set 10 meters back from the edge of the shoreline, and its beacon is 20 meters above sea level. Lucy can see the beacon from her ship, and the angle of elevation is 21. Her eyes are 11 meters above sea level. How far is the ship from the shoreline to the nearest meter?

So the answer is 14m from the ship to the shorline, but I dont know how to get it.. I set up the picture to help me out which was a triangle and had a line between the middle to represent the above and bottom sea level