Help with finding side of a triangle I have a right angled triangle question and have through my working figure out that the angles are $90^\circ$, $67^\circ$, and $23^\circ$. I have one side opposite $23^\circ$ which is $13$cm. I need to find the side length opposite the right angle.
I've tried sine rule and I get a negative number.
$$\sin \frac{23}{13} = \sin \frac{90}{CB}$$
Through rearranging (possibly incorrect?)
$$CB = \frac{\sin 90}{ \frac{\sin 23 }{13}} ≈ -19$$ when typed in my calculator.
What am I doing wrong?
Any help is much appreciated; sorry if the question is very basic.

if so then you have $$\sin(23^{\circ})=\frac{13cm}{c}$$ therefore $$c=\frac{13cm}{\sin(23^{\circ})}$$
