Lines defined for a triangle

median of a triangle

straight line connecting multiple points that can be defined as the center of a triangle, such as the orthocenter, the circumcenter and the centroid

line segment in a triangle

line defined from a triangle and a point on its circumcircle, through the closest point on each side line to the given point

In geometry, a cevian is a line segment which joins a vertex of a triangle to a point on the opposite side of the triangle. Medians, symmedians, angle bisectors, altitudes are all special cases of cevians. The name cevian comes from the Italian mathematician Giovanni Ceva, who proved a theorem about cevians which also bears his name.

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line associated with a triangle centre

geometric term

line segment through vertice of a triangle that bisects its perimeter