Given a triangle ABC, the incenter I, the incircle, and the Gergonne point G. Construct the contact triangle A'B'C' . Adams theorem (1843) states that the parallels to the sides of the contact triangle from G, intersect the side of the triangle ABC in 6 points lying on a circle (Adams' circle) concentric to the incircle. Click the Next button below to start the step-by-step illustration.