Two airplanes leave an airport at the same

time. The velocity of the first airplane is
700 m/h at a heading of 40.5

. The velocity
of the second is 640 m/h at a heading of 120◦
.
How far apart are they after 2.4 h?
Answer in units of m.

make a diagram; use the law of cosines

What is the law of cosines?