In the given figure <C=90 ,<B= 15 degrees.We need to find side c.
The side adjacent to <B is known as adjacent side and the one opposite to it is opposite side .The side opposite to 90 degrees is hypotenuse.
In the figure b=12 is opposite side and c is the hypotenuse.
Sine of any angle is the ratio of opposite and hypotenuse.
SinB=


Cross multiplying we have c= 12 (sin15)
c=12(.2588) [ sin15=.2588]
c=46.37