sin77Sin 77 Degrees The sin of 77 degrees is 0.97437, the same as sin of 77 degrees in radians. To obtain 77 degrees in radian multiply 77° by π 180° = 77180 πCalculate 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.