Orthocenter of a Triangle

A triangle whose mid points in between the sides (6,0),(0,8) and (6,8), the orthocenter of triangle

The orthocenter of the triangle PAB is

H is orthocenter of the triangle ABC, then AH is equal to :

(a,b),(c,d),(e,f) are the vertices of an equilateral triangle.Then the orthocenter of the triangle is

The orthocenter of the triangle formed by (0,0),(8,0),(4,6) is

The orthocenter of the triangle formed by (1,-3),(6,1),(4,-1) is :

The orthocenter of the triangle formed by the lines xy=0 and x+y=1 is

If H is orthocenter of triangle PQR then PH+QH+RH is

If the vertices of a triangle are (sqrt(5),0),(sqrt(3),sqrt(2)), and (2,1), then the orthocenter of the triangle is

A triangle has its vertices on a rectangular hyperbola.Prove that the orthocenter of the triangle also lies on the same hyperbola.