Euler's Method

Euler's Method The circumcenter of a triangle is the intersection of any two of the three perpendicular bisectors. The orthocenter is one of the triangle's points of concurrency formed by the intersection of the triangle's 3 altitudes. The centroid of a triangle is the intersection of the three medians of the triangle.
Plot the circumcenter, orthocenter and centroid. When changing the triangle (by dragging points A, B and C), what do you notice is always true about the circumcenter, orthocenter and centroid? Why do you think this is?