There are a number of interesting ways to define the “center” of a triangle, each with its own special properties. [br][br]The “centroid” of a triangle is the meeting point of the three lines from the midpoints of the triangle’s sides to the opposite vertex. [br]The centroid is the triangle’s “center of gravity.” (If you made a cardboard triangle, it would balance on the centroid.) [br]If you are using a version of GeoGebra that allows you to create custom tools, then create your own tool for constructing a centroid of a triangle. Also, create your own tools for the circumcenter, orthocenter and incenter of a triangle and use these custom tools to construct the Euler segment and the nine-point circle.