==External links==* Derivation of formula for radius of incircle of a triangle===Interactive===*Triangle incenter Triangle incircle Incircle of a regular polygon With interactive animations*Constructing a triangle's incenter / incircle with compass and straightedge An interactive animated demonstration* Equal Incircles Theorem at cut-the-knot* Five Incircles Theorem at cut-the-knot* Pairs of Incircles in a Quadrilateral at cut-the-knot*An interactive Java applet for the incenter
* Derivation of formula for radius of incircle of a triangle* Triangle incenter Triangle incircle Incircle of a regular polygon With interactive animations* Constructing a triangle’s incenter / incircle with compass and straightedge An interactive animated demonstration* Equal Incircles Theorem at cut-the-knot* Five Incircles Theorem at cut-the-knot* Pairs of Incircles in a Quadrilateral at cut-the-knot* An interactive Java applet for the incenter