[b]Leonhard Euler[/b] noticed that, in a triangle that is not equilateral, the [b]Centroid, Circumcenter, and Orthocenter all lie on the same line[/b]. [br][br][color=#0000ff]Experiment with the triangle: select a vertex and move it around to make an acute, right, or obtuse triangle. Can you move the circumcenter and orthocenter outside the triangle? How about the centroid?[br][/color][br][color=#38761d]Can you make the three centers coincide? What kind of triangle do you need to make?[br][/color][br][color=#980000]Check the Perpendicular Bisector box to show them in the triangle. Then try the altitudes and medians.[/color][br]