DEFINITIONS

Orthocenter:The orthocenter of a triangle is the intersection of the three altitudes of the triangle. An altitude is the line that passes through a vertex and is perpendicular to the opposite side of the triangle. Orthocenter is generally denoted by H.Click here for a GSP script for Ortocenter (H) of a triangle ABC.

Circumcenter:The circumcenter of a triangle is the intersection of the three perpendicular bisectors of the triangle. A perpendicular bisectors is the line that passes through the mid-point of one side of the triangle and is perpendicular to that side. Circumcenter is generally denoted by C. Click here for a GSP script for Circumcenter (C) of a triangle ABC.

Circumcircle: A Triangle's circumscribed circle. Its center O is called the Circumcenter, and its Radius R the Circumradius. Click here for a GSP script for Circumcircle of a triangle ABC.

Nine Point Circle: The nine point circle is the circle that ,in a triangle ABC, the midpoints of AB, BC, and AC; the points at the feet of the altitudes;and the midpoints of the segments connecting the vertices of triangle ABC to the orthocenter lye on. Click here for a GSP script for the nine-point circle.

Center of Nine point circle:The center of the nine point circle lies on Euler's Line midway between the circumcenter and the orthocenter. Click here for a GSP script for the center (N) of a nine-point circle.