# length of c when calulating using sines

I cannot understand how i get a negative answer. I have a triangle with three angles and one side. To get another side $c$ I used the below calculation but got a negative answer.

Given that $\frac{c}{\sin C} = \frac{b}{\sin B}$ and the following calculation is made: $$c= \frac{10\times\sin 90}{\sin 68.47}$$ or $c= (10\times 0.894)/ -0.60123$ I get a negative answer for $c$?

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Please have a look at my edit and tell me is it done correctly? – Babak S. Nov 28 '12 at 7:44

@david: In fact, $\sin 90$ is not equal to $0.894$ in any calculator. It is $1$. The same is true for anothe angle. – Babak S. Nov 28 '12 at 7:52