Math Unit 1: Centres of Circles

Centroid

Derived from intersection of median lines, always within triangle

Orthocentre

Derived from intersection of altitude lines (may need to be extended), can be outside triangle

Circumcentre

centre of a circle equidistant to vertices, where all triangle vertices lie on circle, derived from intersection of perpendicular bisectors, can be outside triangle

Median

A line that passes through the midpoint of a triangle and through the opposite vertex

Altitude

A line that passes through a vertex of a triangle and passes through the opposite side at a 90º angles

Perpendicular bisector

line that intersects a line segment at a 90º angle and passes through its midpoint