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Nine-point center
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<p>In <a href="/facts/Geometry/wTQf5ffQ">geometry</a>, the nine-point center is a <a href="/facts/Triangle_center/FKfm090E">triangle center</a>, a point defined from a given <a href="/facts/Triangle/cRXUwsMn">triangle</a> in a way that does not depend on the placement or scale of the triangle. It is so called because it is the center of the <a href="/facts/Nine-point_circle/0UfSxFX9">nine-point circle</a>, a circle that passes through nine significant points of the triangle: the <a href="/facts/Midpoint/ykRvr0Vk">midpoints</a> of the three edges, the feet of the three <a href="/facts/Altitude_(triangle)/z9H8fFMz">altitudes</a>, and the points halfway between the <a href="/facts/Orthocenter/z9H8fFMz">orthocenter</a> and each of the three vertices. The nine-point center is listed as point X(5) in <a href="/facts/Clark_Kimberling/WMRRw662">Clark Kimberling</a>'s <a href="/facts/Encyclopedia_of_Triangle_Centers/ClS9kJor">Encyclopedia of Triangle Centers</a>. </p>