The orthocenter of the triangle
The orthocenter of a triangle is the intersection point of the triangle heights or their extensions. Depending on the type of triangle, the orthocenter can be inside the triangle (in an acute angle), outside it (in an obtuse angle) or coincide with the vertex (in a rectangular one – coincides with the vertex at a right angle).
.The orthocenter of the triangle through the coordinates of the vertices
H=