nine-point circle

noun

That circle which passes through the feet of the altitudes of a given triangle.

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Meanings

nounnine-point circle (plural nine-point circles)

plural nine-point circles · alternative nine points circle

  1. That circle which passes through the feet of the altitudes of a given triangle.

Origin

So called because the circle passes through nine points of interest: the feet of the three altitudes, the centers of the three sides, and the midpoints of the segments which join the triangle's vertices with its orthocenter.

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Cite this entry
APA

nine-point circle. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/nine-point%20circle

MLA

“nine-point circle.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/nine-point%20circle. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “nine-point circle,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/nine-point%20circle.

Source: nine-point circle on Wiktionary, CC BY-SA 4.0.