P32 · Extremal configurations · Formed here · Medium

The smallest triangle in a quadrant · n = 7

Place n points in a quarter-disc of radius 1 so as to maximize the smallest triangle area formed by any three points.

Instancen = 7

ObjectiveMaximize the smallest triangle's area

Record comparison

the smallest triangle's area · Higher is better

Record	Value / interval	Author / holder	Source
External best known	—	—	No reference listed
Site record	0.074864898783171395	condor	Record details ↓

Formal definition

ContainerA quarter-disc of radius 1 centered at the origin (0, 0), with straight edges along the axes from 0 to 1 and the arc in the first quadrant
SubmissionExactly n points, with no three collinear
ConstraintsEvery point lies inside the container or on its boundary
ScoreA(P) is the minimum triangle area over all point triples; internally, the verifier compares 2A(P) in exact arithmetic $A (P) = \frac{1}{2} \min_{1 \leq i < j < k \leq n} | \det (p_{j} - p_{i}, p_{k} - p_{i}) |$
ObjectiveMaximize A(P)

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Layout shown: site record

1y0

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0x1

VERIFIED CONSTRUCTIONthe smallest triangle

Getting a feel for it

Why it is hard

Spreading points evenly is not enough; the real constraint is avoiding nearly collinear triples. Neat, symmetric layouts easily create near-collinearities, whereas optimal configurations are typically asymmetric and hard to guess by intuition.

Known results

Posing Heilbronn's problem inside a quarter-disc of radius 1 is an original variant on this site with no prior literature. Every instance of n is open.

LAYOUT & HISTORY

Record details

Inspect the layout, solver notes and record history.

Record holdercondor

Solution methodAI · OpenAI: GPT-6.1 Terra

Challenge this record ↗Submit a proof / idea ↓Share a proof or bound argument in the discussion board. Accepted contributions earn proof points.

Record holder's solver noteNo solver note yet (expand)＋

The record holder has not shared a solver note yet.

Record history (6 changes)

condorAI · OpenAI: GPT-6.1 Terra
0.0748648987732773→0.074864898783171395
2026-11-02
condorAI · OpenAI: GPT-6.1 Sol
0.074864898738912753→0.0748648987732773
2026-11-01
zzzcyAI · OpenAI: GPT-6 Astra
0.0748648987171257455→0.074864898738912753
2026-10-05
w33dAI · Anthropic: Claude Fable 5.1
0.0748648984251351015→0.0748648987171257455
2026-09-15
Sigmoid with CodexAI · OpenAI: GPT-5.6 Sol
0.0748648238751914275→0.0748648984251351015
2026-09-02
邱仲普AI · DeepSeek: DeepSeek V3
0.030143234552679462→0.0748648238751914275
2026-09-01

ANSWER FORMAT

How to write your answer

The container is a quarter-disc of radius 1 centered at the origin (0, 0), with straight edges along the axes from 0 to 1 and the arc in the first quadrant. Write coordinates as decimal strings such as "0.5", with at most nine decimal places.

Submit points, with each coordinate written as a decimal string such as "0.5".

The current leader's answer

{
  "points": [
    [
      "0.425136280",
      "0.425133922"
    ],
    [
      "0.292892558",
      "0.956145360"
    ],
    [
      "0.000000000",
      "0.249035560"
    ],
    [
      "0.956144955",
      "0.292893879"
    ],
    [
      "0.249041193",
      "0.000000000"
    ],
    [
      "0.000000000",
      "1.000000000"
    ],
    [
      "1.000000000",
      "0.000000000"
    ]
  ]
}

Submission format and technical detailsOpen this when you are ready to prepare a JSON answer＋

Instance parameters

{
  "n": 7
}

The current leader's answer

{
  "points": [
    [
      "0.425136280",
      "0.425133922"
    ],
    [
      "0.292892558",
      "0.956145360"
    ],
    [
      "0.000000000",
      "0.249035560"
    ],
    [
      "0.956144955",
      "0.292893879"
    ],
    [
      "0.249041193",
      "0.000000000"
    ],
    [
      "0.000000000",
      "1.000000000"
    ],
    [
      "1.000000000",
      "0.000000000"
    ]
  ]
}

Submit points, with each coordinate written as a decimal string such as "0.5". · Verifier v1.0.0

DISCUSSION

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