Every triangle can be inscribed in some circle or we can say that every circle has an inscribed triangle. This circle is called circumcircle or circumscribed circle.
Every triangle has an inscribed circle, called the inscribed circle or incircle.
Not all polygons can be inscribed or circumscribed about a circle. However, every regular polygon with 3 or more sides has an inscribed circle, called its incircle,
and every regular polygon with 3 or more sides can be inscribed in some circle, called its circumcircle.
Drag the slider on the applet to verify this particular property of inscribed or circumscribed regular polygon.
Can you construct an inscribed or circumscribed circle of any regular polygon?