Question

Two ships A and B sail simultaneously from the same place. vessel A on course 300at 15 knots and B on course N 45°E at 10 knots. After 1 hour and 30 min, how far is vessel A to vessel B?

Answer 1

As theorem of cosine

$c^2=a^2+b^2-2abcos \alpha$

a=15x1.5=22.5 knocks

b=10x1.5=15 knocks

$c=\sqrt{22.5^2+15^2-2x22.5x15xcos (45°)}=\sqrt{506.25+225-477.3}=\sqrt{253.95}=15.9 knokcs$