Mark notices that the bearing of a tree on the opposite bank of a river flowing north is 115.45°. Lisa is on the same bank as Mark, but 428.3 meters away. She notices that the bearing of the tree is 45.47°. The two banks are parallel. What is the distance across the river?

Question

Mark notices that the bearing of a tree on the opposite bank of a river flowing north is 115.45°.  Lisa is on the same bank as Mark, but 428.3 meters away.  She notices that the bearing of the tree is 45.47°.  The two banks are parallel.  What is the distance across the river?

anonymous · Answer

I'm going to attempt to draw a picture

anonymous · Answer

Okay so it wouldn't let me post my drawing

anonymous · Answer

give me one moment, i'll do some research.

anonymous · Answer

Picture really isn't necessary, so you have north at 115.54°. Mark is 428.3 meters away so in that case, 45.47°. Since the two banks are parrell it may be a bit more harder. 115.54, 428.3 / 2. - 45.47 [] x. would equal down to; 293.4 m. Not much really to explain.

anonymous · Answer

so in conclusion; 293.4 m is your answer.

anonymous · Answer

Ahhhhh okay I getcha. Thank you!