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.
(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?