A tanker is moving 5 nautical miles (5 knots) on bearing 105 degrees.at 1100 hours (11am) the tanker obserbs a lighthouse on bearing 040 degrees. at midday the lighthouse bears 340 degrees. Draw a well labelled diagram to show the movement of the tanker between 11am and midday. calculate the distance in nautical miles from the tanker to the lighthouse at midday.

I know the angle LH is 40 degrees

but i still get confused in finding the angles for P1200 and P1100.

The length from P1100 to P1200 is 5nm. I use the SIN rule for non right angle trig.

so

SIN 5nm SIN ??????

sin 40degrees equals sin ??????

How do I work this out?

I need the answer 12 hours from now

thanks.