Pedoe's inequality

proper noun

The observation that, if a, b, and c are the lengths of the sides of a triangle with area ƒ, and A, B, and C are the lengths of the sides of another triangle with area F, then A²(b²+c²-a²)+B²(a²+c²-b²)+C²(a²+b²-c²)≥16Ff,, with equality if and only if the two triangles are similar with pairs of corresponding sides (A, a), (B, b), and (C, c).

Meanings

proper noun
  1. geometryThe observation that, if a, b, and c are the lengths of the sides of a triangle with area ƒ, and A, B, and C are the lengths of the sides of another triangle with area F, then A²(b²+c²-a²)+B²(a²+c²-b²)+C²(a²+b²-c²)≥16Ff,, with equality if and only if the two triangles are similar with pairs of corresponding sides (A, a), (B, b), and (C, c).

    Synonyms: Neuberg-Pedoe inequality

Synonyms & antonyms

proper nounThe observation that, if a, b, and c are the lengths of the sides of a triangle with area ƒ, and A, B, and C are the lengths of the sides of another triangle with area F, then A²(b²+c²-a²)+B²(a²+c²-b²)+C²(a²+b²-c²)≥16Ff,, with equality if and only if the two triangles are similar with pairs of corresponding sides (A, a), (B, b), and (C, c).

Origin

Named after Daniel Pedoe.

Full word history & related roots →
Cite this entry
APA

Pedoe's inequality. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/Pedoe's%20inequality

MLA

“Pedoe's inequality.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Pedoe's%20inequality. Accessed November 5, 2026.

Chicago

WatkinsX Dictionary, s.v. “Pedoe's inequality,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/Pedoe's%20inequality.

Source: Pedoe's inequality on Wiktionary, CC BY-SA 4.0.