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?
answer:
so it would be c^2=a^2+b^2-2ab cos C
900^2+1260^2-2(900)(1260)(cos75)
c^2=33542.9
c=183.14km
is it right?

1 answer

c^2 = 900^2+1260^2-2(900)(1260)(cos75) correct
= 810,000 + 1,587,600 - 587,001.59
= 1,810,598.4 (you had 33542.9)
c = √1,810,598.4
c = 1345.58