posted by Tareena-- drwls check my answer please .
Two Planes leave an airport at the same time, one flying 300km/h and the other at 420km/h
The angle between their flight paths is 75 degrees after three hours, how fart apart are they?
so it would be c^2=a^2+b^2-2ab cos C
is it right?
Right equation, but you did not do it correctly.
c^2 = 810,000 + 1,587,600 - 587,002
c = 1345 km