Relationships in Triangles
Perpendicular bisectors and the circumcenter, angle bisectors and the incenter, medians and the centroid, altitudes and the orthocenter, the midsegment theorem, and inequalities inside one triangle.
Builds on
Triangle congruence from Unit 4 (SSS·SAS·ASA·AAS·HL and CPCTC power every proof here), plus midpoints, perpendiculars, and angle bisectors from Unit 1 and distance-to-a-line from Unit 3.
Lessons