Photos of Interactive Mathematics Miscellany and Puzzles
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Mean Area Lemma A, B, C, D are concyclic points on a circle (O) and AC perpendicular with BD. Denote [X] as area of X. Prove that: ([AED] + [BEC])/2 = [AOB] Remark: It is interesting that this lemma can be used for new proof of Pythagorean theorem. |
