sin77Use our sin(x) calculator to find the sine of 77 degrees - sin(77 °) - or the sine of any angle in degrees and in radians.Calculate the value of the sin of 720 ° To enter an angle in radians, enter sin(720RAD) sin(720 °) = -4.89842541528951E-16 Sine, in mathematics, is a tronometric function of an angle.