sin77Note that sin77° is periodic: sin (77° + n × 360°) = sin 77 degrees, n$hspace in hspace mathbb$. There are more formulas for the double angle (2 × 77°), halfSin 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 π