[size=100][size=150]Euler, on the hunt for something else, [i]accidentally[/i] discovered this fascinating fact about triangle centers. [/size][/size]
Well, the [color=#c27ba0]circumcenter[/color], [color=#6aa84f]orthocenter[/color], and [color=#3d85c6]centroid[/color] all fell on the same line!
The line that passes through the three distinguished points - [color=#a64d79]circumcenter[/color], [color=#6aa84f]orthocenter[/color], and [color=#3c78d8]centroid[/color] - is called the [b][color=#bf9000]Euler Line[/color][/b]. [br][br][size=85][i]There's a few other points on this line as well, but we will get to that in a moment.[/i][/size]
[size=150][b][br][br]I KNOW RIGHT![/b][/size]
The[b] [color=#bf9000]Euler line [/color][/b]exists for all triangles... except [u]one[/u] kind. As you watch the animation below, think back to the triangles from the previous activities. Was there ever a special case?
When [b]DON'T[/b] these three points create a line?
When the triangle is equilateral! [br][br]The lines that create these triangle centers become concurrent, and therefore the intersections create [u]one[/u] point of concurrency. Since you need more than one point to create a line, we can say that the Euler line does not exist for equilateral triangles.
The three points we talked about aren't the only ones on the Euler line. Aside from the orthocenter, circumcenter, and centroid, some other points that fall on this line are...[br][br]Center of the Nine Point Circle[br]Schiffler's Point [br]Exeter Point [br]Longchamps Point [br]Gossard Prospector[br]Incenter [color=#666666](only if the triangle is isosceles)[/color]