geometry

circumcenter

the point of concurrency of the perpendicular bisector of the sides of the triangle

altitude

perpendicular segment for a vertex to the line containing the side opposite that vertex

incenter

the point of concurrency of the angle bisectors of the triangle

centroid

point of concurrency of the medians of the triangle

concurrent

3 or more lines if they intersect at one point

equidistant

from 2 objects if it is the same distance from all of the objects

orthocenter

the point of concurrency of the lines containing the altitudes of the triangle

median

a segment that has as its endpoints at a vertex of the triangle and the midpoint of the opposite side

perpendicular bisector

a segment, line, or ray that’s perpendicular to the segment and divides the segment into two congruent segments

midsegment

a segment that joins the midpoints of two sides of a triangle