Question

A triangle has sides A, B, and C. Sides A and B are of lengths `5` and `3`, respectively, and the angle between A and B is `pi/3`. What is the length of side C?

Answer 1

Length of side `C` is `4.36 (2dp)` unit.

Explanation:

Sides `A=5 , B=3` and angle `/_c=pi/3=180/3=60^0`. Applying cosine law we can find `C= sqrt(A^2+B^2 -2*A*B*cosc)`

or `C=sqrt(5^2+3^2 -2*A*B*cos60) = sqrt(25+9 -cancel2*5*3* 1/cancel2) = sqrt 19 =4.36(2dp)` unit.

Length of side `C` is `4.36 (2dp)` unit. [Ans]