the sine of an angle is opposite over hypotenuse: O/H
so sin(C): using C as your angle the side 'O' is opposite to your angle, in this case, 5. and H is the hypotenuse, the longest side of the triangle, or the side opposite to the right angle, in this case 13.93
sin(C) = 5/13.93
= 0.36 (2d.p.)
