Lesson 5.2: Medians and Altitudes of Triangles
Medians and Altitudes of Triangles
Median of a Triangle
A median is a segment from a vertex to the midpoint of the opposite side. Every Triangle has three medians.
Centroid
The three medians are concurrent at the centroid.
- The centroid divides each median in a 2:1 ratio from the vertex.
- The centroid is the center of gravity (balance Point) of the Triangle.
- The centroid is always inside the Triangle.
- Centroid formula: ((x₁+x₂+x₃)/3, (y₁+y₂+y₃)/3)
Altitude of a Triangle
An altitude is a perpendicular segment from a vertex to the Line containing the opposite side (the base). Every Triangle has three altitudes.
Orthocenter
The three altitudes are concurrent at the orthocenter.
- In an acute Triangle, the orthocenter is inside.
- In a right Triangle, the orthocenter is at the right-Angle vertex.
- In an obtuse Triangle, the orthocenter is outside.
Summary of Triangle Centers
| Center | Formed By | Property |
|---|---|---|
| Circumcenter | Perpendicular bisectors | Equidistant from vertices |
| Incenter | Angle bisectors | Equidistant from sides |
| Centroid | Medians | Balance Point (2:1 ratio) |
| Orthocenter | Altitudes | Perpendicular from vertex to opposite side |