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°), half(@susan.sin77) • photos and videos. . Log in. Open app. susan.sin77's profile picture. 6 posts. 55 followers. 120 following. susan.sin77.