A listing, with description and illustration, of 20th-century triangle centers (including: Schiffler Point, Exeter Point, Parry Point, congruent isoscelizers point, Yff Center of Congruence, isoperimetric point and equal...

This geometry lesson from Illuminations presents the Triangle Classification problem. Students will attempt to classify the triangles formed in a plane when a randomly selected point is connected to the endpoints of a...