What is the sine of a 30 degree angle in a right triangle?

The sine of a 30-degree angle in a right triangle is 0.5. This is derived from the ratio of the length of the side opposite the angle to the length of the hypotenuse. In a 30-60-90 triangle, the sides are in the ratio 1:√3:2, making the sine of 30 degrees equal to 1/2.