A triangle has sides A, B, and C. The angle between sides A and B is (2pi)/3. If side C has a length of 32 and the angle between sides B and C is pi/12, what is the length of side A?

1 Answer
Jan 9, 2017

A=16/3(3sqrt(2)-sqrt6)

Explanation:

You would apply the Law of Sines:

color(red)(A/sin hat(BC))=B/sin hat(AC)color(red)(=C/sin hat(AB))

Then

A/sin(pi/12)=32/sin((2pi)/3)

and

A=(32*sin(pi/12))/(sin((2pi)/3))=(cancel32^8*(sqrt(6)-sqrt(2))/cancel4)/(sqrt(3)/2)=16(sqrt(6)-sqrt(2))/sqrt(3)

=16*(sqrt(18)-sqrt(6))/3=16/3(3sqrt(2)-sqrt6)