| Term | Definition |
| Angle Bisector | Bisects an angle into 2 congruent angles; center of inscribed circle equidistant from sides of triangle |
| Incenter | Point of Concurrency for Angle Bisector |
| Perpendicular Bisector | segment that is perpendicular to the side of a triangle and goes thru midpoint |
| Circumcenter | Point of Concurrency for Perpendicular Bisector |
| Median | Segment from a vertex to the midpoint of opposite side |
| Centroid | Point of Concurrency for Median |
| Altitude | Segment from a vertex that is perpendicular to opposite side |
| Orthocenter | Point of Concurrency for Altitude |