why is sqrt(10/sin60) called "invalid argument for sqrt" by this calculator?

$${\sqrt{{\frac{{\mathtt{10}}}{\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{sin}}{\left({\mathtt{60}}^\circ\right)}}}}} = {\mathtt{3.398\: \!088\: \!489\: \!695\: \!106}}$$

Works fo me :)