# Bearing Help

• Jan 6th 2008, 04:19 AM
nugiboy
Bearing Help
Hi guys.
Im a bit stuck on this bearing question and need a bit of help.

-
At 12:00 the captain of a ship observes that the bearing of a lighthouse is 340'. His position is
at A.
At 12:30 he takes another bearing of the lighthouse and finds it to be 030'. During this time
the ship moves on a constant course of 280' to the point B.
His plot on the chart is as shown in Fig 11 below.

http://i137.photobucket.com/albums/q.../MathsHelp.jpg

(i) Write down the size of the angles LAB and LBA.
-

I worked out LAB to be 60' because i knew that the course to be was 280' which was pretty easy. Im really stuck on angle LBA though. Any suggestions?
• Jan 6th 2008, 04:54 AM
earboth
Quote:

Originally Posted by nugiboy
Hi guys.
Im a bit stuck on this bearing question and need a bit of help.

-
At 12:00 the captain of a ship observes that the bearing of a lighthouse is 340'. His position is
at A.
At 12:30 he takes another bearing of the lighthouse and finds it to be 030'. During this time
the ship moves on a constant course of 280' to the point B.
His plot on the chart is as shown in Fig 11 below.

http://i137.photobucket.com/albums/q.../MathsHelp.jpg

(i) Write down the size of the angles LAB and LBA.
-

I worked out LAB to be 60' because i knew that the course to be was 280' which was pretty easy. Im really stuck on angle LBA though. Any suggestions?

Hello,

I've modified your sketch. (see attachment)
• Jan 6th 2008, 05:11 AM
nugiboy
Quote:

Originally Posted by earboth
Hello,

I've modified your sketch. (see attachment)

Thanks for that. You made it alot clearer. I forgot that parrallel opposite angle rule you used to get the angle L.