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== Orthocenter of a Triangle ==
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From Greek: orthos -
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"straight, true, correct, regular" The point where the
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three altitudes of a triangle intersect. One of a triangle's points
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of concurrency.
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Try this Drag the
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orange dots on any vertex to reshape the triangle. Notice the
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location of the orthocenter.
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The altitude of a triangle (in the sense it used
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here) is a line which passes through a vertex of the triangle and is
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perpendicular to the opposite side. There are therefore three
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altitudes possible, one from each vertex. See Altitude definition.
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It turns out that all three altitudes always
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intersect at the same point - the so-called orthocenter of the
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triangle.
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The orthocenter is not always inside the triangle.
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If the triangle is obtuse, it will be outside. To make this happen
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the altitude lines have to be extended so they cross. Adjust the
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figure above and create a triangle where the orthocenter is outside
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the triangle. Follow each line and convince yourself that the three
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altitudes, when extended the right way, do in fact intersect at the
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orthocenter.
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* Direct substitution
* Direct substitution
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== Evaluation ==
== Evaluation ==