géométrie prépa recueilchapitre 4problème 4.1vecteurs

A relation on the diagonals

Recueil COMIMa — Techniques de résolution de problèmes · 2026 · Madagascar · ★★★★★

Statement

Montrer que \[ |AC|^2 + |BD|^2 = |AB|^2 + |BC|^2 + |CD|^2 + |DA|^2 \iff A + C = B + D. \]

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Origin : Recueil COMIMa — Techniques de résolution de problèmes · 2026 · Madagascar

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