Basic trig bearing problem

FYI - I'm doing this not as homework but as revision, I'm not asking for the answer, I want to know the process in which the answer was found.

"A 4WD vehicle leaves a camp site and dravels across a flat, sandy plain in a direction of S 65 degrees E, for a distance of 8.2km. It then heads due south for 6.7km to reach a waterhole."

The two questions are:

a) How far is the waterhole from the camp site?

b) What is the bearing of the waterhole from the camp site?

I don't remember doing this in class and I've tried many things but I can't get the answer. I've got a correct (I think) diagram, but I don't know where to start. Can you help?

Thanks in advance.