Question

What is the exact area of triangle with measures a=6 b=7 and cos C= 1/4

Answer 1

The area of the triangle is A= (1/2)absinγ

(sinγ)Λ2+(cosγ)Λ2=1 => sinγ=√1-(cosγ)∧2= √1- (1/4)∧2=√1-(1/16)=√(15/16)=√15/4

A=(1/2)*6*7*√15/4=21*√15/4=(21/4)√15

Good luck!!!