What is an orthocenter? Here are some definitions.
Noun
(geometry): the intersection of the three lines that can be drawn flowing from the three corners of a triangle to a point along the opposite side where each line intersects that side at a 90 degree angle; in an acute triangle, it is inside the triangle; in an obtuse triangle, it is outside the triangle.
Examples
The orthocenter is one of the four concurrency points in a triangle.