Points of Concurrency

Click and drag points Q, R, and S to resize triangle QRS. Use the checkboxes to show/hide constructions.

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1. The perpendicular bisectors of the sides of a triangle are concurrent at the CIRCUMCENTER. The circumcenter is equidistant from the vertices of the triangle.
2. The angle bisectors of the vertices of a triangle are concurrent at the INCENTER. The incenter is equidistant from the sides of the triangle.
3. The medians of a triangle are concurrent at the CENTROID. The centroid is two-thirds the distance from each vertex to the midpoint of the opposite side.
4. The altitudes of a triangle are concurrent at the ORTHOCENTER.

Michelle Krummel, June 2, 2010, Created with GeoGebra