Solve the all parts of following question given below:

Question: A pilot in a small plane encounters shifting winds. He flies 30.0km at 30 degrees north of east, then 50.0km due north. From this point, he flies an additional distance in an unknown direction, only to find himself at a small airstrip that his map shows to be 90.0km directly north of his starting point.

Part I: What was the length of the third leg of his trip?

Part II: What was the direction of the third leg of his trip?

I need expert help to solve the above question and do not use the standard angle. Instead give the direction as how many degrees north of west.