Here's an easy way to visualize it

First, think of the angle formed by two intersecting lines that are each tangent to a given circle. Isolate the lines and the arc that they include; you should get something that looks like an isosceles triangle, but with a circular arc in place of the base. You can then trace the arc with as many distinct lines as you want, whether it be 2, 3, 5, or 143209, and get a polygon where 3 angles are acute and the rest are reflex.