a ship observes a lighthouse in a direction 50°W of N.After

a ship observes a lighthouse in a direction 50°W of N.After sailing 36 km in a direction 35°W of S the lighthouse is observed in a direction 15°E of N.
a) a draw a sketch showing the information given.
b) calculate the distance of the ship from the lighthouse when the second observation is made.
顺便求翻译题目orz。