IMO 2010 Problem 2: Euclidean-geometry translation

Let ABC have circumcenter O and incenter I. Let D be the second intersection of AI with the circumcircle, choose F on BC, and choose E on the circumcircle with ∠(AE,AC)=∠(AB,AF). Let G be the midpoint of IF and K=DG∩EI. Prove OK=OA.

This page concerns the specialized translated task used in the IMO-AG-30 benchmark. The study’s aggregate result does not establish whether this individual task was solved.

Why it matters and what counts as progress

Why it matters: It connects an angle-constrained chord construction with a final circumcircle-membership statement.

What counts as progress: A proof that K lies on the circumcircle under the translated directed-angle and midpoint conditions.

How the problem developed

  1. 2010 · Contest appearance [1][3]

    International Mathematical Olympiad The official archive lists this as IMO 2010 P2; it is one of the contest problems later encoded in the specialized IMO-AG-30 geometry language.

  2. 17 Jan 2024 · Benchmark result [2][3]

    Trieu H. Trinh, Yuhuai Wu, Quoc V. Le, He He, and Thang Luong (AlphaGeometry) The Nature paper reports AlphaGeometry solved this translated benchmark statement using language-model auxiliary constructions and symbolic deduction/algebra. The paper includes the benchmark proof in its supplement.

  3. 5 Feb 2025 · Benchmark result [4][5][3]

    Yuri Chervonyi, Trieu H. Trinh, Miroslav Olšák, Xiaomeng Yang, Hoang H. Nguyen, Marcelo Menegali, Junehyuk Jung, Junsu Kim, Vikas Verma, Quoc V. Le, and Thang Luong (AlphaGeometry2) The AlphaGeometry2 paper reports solving all 30 statements in the original IMO-AG-30 benchmark, which includes this formalized target. This is a system result on the benchmark encoding, not an independent review of the original contest wording.

AI contribution

AlphaGeometry solves 25 translated Olympiad geometry problems

AlphaGeometry solved 25/30 specialized IMO-AG-30 classical Euclidean geometry translations using learned auxiliary-point constructions plus a symbolic deduction and algebra engine; the paper does not claim all natural-language IMO geometry conditions are represented.

AI involvementAI-centered
ImportanceNotable
Human understandingFull
Reported

Sources

  1. IMO 2010 Problems (official archive)
  2. Trinh et al., Solving olympiad geometry without human demonstrations
  3. AlphaGeometry IMO-AG-30 formalized problem set
  4. Chervonyi et al., Gold-medalist Performance in Solving Olympiad Geometry with AlphaGeometry2
  5. AlphaGeometry2 paper, arXiv record
  6. Trinh and collaborators: Solving olympiad geometry without human demonstrations
  7. AlphaGeometry source and proof artifacts
  8. DeepMind account of computer checking
  9. Precise translated question and assumptions
  10. AlphaGeometry study and benchmark results
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