en.wikipedia.org/wiki/Altitude_(triangle)

In geometry, an altitude of a triangle is a line segment through a vertex and
perpendicular to a line containing the base This line ...

www.mathopenref.com/triangleorthocenter.html

The altitude of a triangle (in the sense it used here) is a line which passes
through a vertex of the triangle and is perpendicular to the opposite side. There
are ...

www.mathopenref.com/constorthocenter.html

How to construct the orthocenter of a triangle with compass and straightedge or
ruler. The orthocenter is the point where all three altitudes of the triangle ...

www.dummies.com/education/math/geometry/how-to-find-the-incenter-circumcenter-and-orthocenter-of-a-triangle/

Every triangle has three “centers” — an incenter, a circumcenter, and an
orthocenter — that are located at the intersection of rays, lines, and segments ...

jwilson.coe.uga.edu/EMAT6680Fa09/DeGeorge/Assign4TdeG/Orthocenters.html

The orthocenter of a triangle is the intersection of the three altitudes of a triangle.
Remember, the altitude of a triangle is a perpendicular segment from the vertex ...

www.ask.com/youtube?q=Orthocenter of a Triangle&v=cmVi6d45zOc

Jan 15, 2013 ... Finding the orthocenter of a triangle doesn't have to be the most difficult thing you
attempt to do in a day. Find the orthocenter of a triangle in ...

www.ask.com/youtube?q=Orthocenter of a Triangle&v=yOhjC_Tej7Q

Dec 10, 2012 ... Finding the orthocenter using coordinates ... How to Find the Orthocenter of a
Triangle in Easy Steps : High School Math - Duration: 1:49.

patch.com/new-jersey/wyckoff/find-orthocenter-of-a-triangle-geometry_eb93cdab

Jan 20, 2014 ... The orthocenter is the intersecting point for all the altitudes of the triangle. One of
the traditional questions in the Geometry class is to find the ...

formulas.tutorvista.com/math/orthocenter-formula.html

Orthocenter of a triangle is the point of intersection of all the altitudes of the
triangle. The orthocenter of a triangle is denoted by the letter 'O'. There is no
direct ...

www.mathwarehouse.com/geometry/triangles/triangle-concurrency-points/orthocenter-of-triangle.php

Orthocenter of a triangle. Explained with examples , illustrations and a cool
HTML5 Applet --for acutes, obtuse and right triangles.