A boat soils 4km on a bearing 038degree and then 5km on a bearing of 067degree.(a)how far is the boat from its starting point? (b)calculate the bearing of the boat from its starting point?

Bearing from the point after 4km to the starting point is 180-038=142degree.
So if you draw the 4km line and 5km lines on a piece of paper, there are 3 angles around that point 4km from the starting point, with 142 and 67 degree.
Find the last angle which is 360-142-67=151 degree.

a)
Using the cosine rule,
the distance=√(4x4+5x5-2x4x5xcos151)
=√75.98479
=8.71693
=8.72 (3s.f.)

b)
Using Sin rule,
sin151 / 8.71693=sinX / 5
sinX=0.27809
X=016.14624 degrees (5d.p.)

bearing of the boat from its starting point=016.14624+038
=054.1 degree

:D
Good Luck!