The value of sin 0 is 0. In trigonometry, the sine function defines a relation between the angle and the perpendicular side and hypotenuse side of a right-angled triangle. The sine of an angle theta is a ratio of the length of the opposite side, perpendicular, and hypotenuse of the right-angled triangle. For sin 0 degrees, the angle 0° lies on the positive x-axis, which means that the value of the opposite side or perpendicular is zero, and the value of the hypotenuse is 1. Therefore, if we place the values in the sin ratio for θ=0°, perpendicular side= 0, and hypotenuse as 1, then we get, sin 0° = 0/1 or sin 0° = 0.

The unit circle is a useful tool to evaluate the sine of an angle. The y-coordinate of the point on the unit circle corresponding to an angle is equal to the sine of that angle. Since the point on the unit circle corresponding to 0° lies on the x-axis, the y-coordinate is 0, and therefore, the sine of 0° is 0.