Hi maths gurus.

I'm in need of some help here with the sine rule.

I have my sine rule values 3.1/sin20 = 5/sineB = 6/SineC

I am trying to find the value for the sine of B so what I did was 3.1/Sine(20)*5 to get 1.81 If I do the inverse sine it comes up with an error on my calculator so is this what I'm meant to do or what?