Question

A triangle has sides A, B, and C. Sides A and B are of lengths `8` and `2`, respectively, and the angle between A and B is `(2pi)/3`. What is the length of side C?

Answer 1

The length of side `C` is `9.17 (2dp)`

Explanation:

Given `A=8 , B= 2 , /_c= (2*pi)/3 =(2*180)/3=120`

Applying cosine law we get `C=sqrt(A^2 +B^2 -2*A*B*cosc) or C=sqrt(64+4-32*cos 120) = sqrt (68 - 32*(-0.5))=sqrt(68+16)=sqrt 84 ~~ 9.17(2dp)` unit [Ans]