Linked from

The 16 pages that link to Orthocenter, each with the reason it gives.

• CentroidCompared with: It is defined by perpendicular lines, not by a balance condition.

• CircumcircleRelated: It is a distinct center whose location, together with the circumcenter, determines Euler’s line.

• CircumcenterCompared with: It is defined by perpendicular altitudes rather than equal vertex distances.

• IncenterCompared with: The orthocenter comes from perpendicular altitudes, not internal angle bisectors.

• Ceva's theoremBroader topic: Ceva can test altitude concurrency using directed ratios, including obtuse triangles.

• Triangle geometryBroader topic: Its position follows from the perpendicular lines drawn from vertices to opposite sides.

• IncircleCompared with: It is a notable triangle center defined by perpendiculars, unlike the incenter’s angle bisectors.

• Euler lineRelated: It is the other defining endpoint of the Euler line’s center alignment.

• Nine-point circleRelated: Three of the circle’s points are the feet of the altitudes through the vertices.

• Simson lineRelated: Special choices of the circle point relate Simson constructions to altitude geometry.

• Triangle centersBroader topic: It is the center defined by perpendiculars from vertices to opposite sides.

• Feuerbach's theoremRelated: Its midpoint with the circumcenter is the nine-point center.

• Fagnano's problemRelated: Its position inside an acute triangle determines the right-angle relations among orthic-triangle vertices.

• Bottema's theoremRelated: It is the familiar concurrency point defined by perpendiculars in triangle geometry.

• Droz-Farny line theoremRelated: Both perpendicular lines in the theorem pass through this point.

• Incenter–excenter lemmaCompared with: It arises from perpendicularity rather than angle-bisector distances.