P83 · Packing and covering · Classic · Hard

Equilateral triangles in a square · n = 34

Pack n unit-side equilateral triangles into a square. Contact is allowed; interiors cannot overlap. Minimise the container square side.

Instancen = 34
ObjectiveMinimize container square side

Record comparison

container square side · Lower is better
RecordValue / intervalAuthor / holderSource
External best known[4.09088, 4.09089)34. Found by Jake LoydErich Friedman ↗
Site recordNo player record yet——

Formal definition

  • ContainerThe editor and certificate normalise the container to the unit square [0,1]², while public scores are reported in the literature's unit-piece scale. Boundary contact is allowed.
  • SubmissionSubmit {radius, placements:[{x,y,turn},…]}, with each value written as a decimal string of at most nine places. Here x, y are centre coordinates; circles require turn = 0 and polygons use turn = tan(θ/2). Coordinates and turn must lie in [−4, 4], with 0 < radius ≤ 4.
  • ConstraintsExactly n congruent pieces lie wholly inside the container with pairwise disjoint interiors. Polygons may rotate independently by arbitrary angles.
  • PrecisionInput decimals are parsed as exact rationals and regular-polygon vertices are defined algebraically, with zero floating-point tolerance in feasibility checks.
  • ObjectiveContainer square side = 1/(2 sin(π/3) r), where smaller is better. Pages, leaderboards, and literature records share this unit with automatic conversion.
Open full editor ↗

Layout shown: starter layout

VERIFIED CONSTRUCTIONVERIFIED CONSTRUCTION

Getting a feel for it

Literature targets and coordinate certificates

Literature targets are converted at their published precision, while nine-decimal coordinate certificates are stored and displayed alongside the source values.

Source
The current arrangement for Equilateral triangles in a square n = 34
LAYOUT & HISTORY

Starter layout

Inspect the layout, solver notes and record history.

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

How to write your answer

the unit square [0,1]²

Submit {radius, placements:[{x,y,turn},…]}, with each value written as a decimal string of at most nine places. Here x, y are centre coordinates; circles require turn = 0 and polygons use turn = tan(θ/2). Coordinates and turn must lie in [−4, 4], with 0 < radius ≤ 4.

Starter answer

{
  "placements": [
    {
      "turn": "0.267949192",
      "x": "0.122222905",
      "y": "0.929434573"
    },
    {
      "turn": "0.267949192",
      "x": "0.366668715",
      "y": "0.929434573"
    },
    {
      "turn": "0.267949192",
      "x": "0.611114524",
      "y": "0.929434573"
    },
    {
      "turn": "0.267949192",
      "x": "0.855560334",
      "y": "0.929434573"
    },
    {
      "turn": "-0.267949192",
      "x": "0.244445810",
      "y": "0.858869146"
    },
    {
      "turn": "-0.267949192",
      "x": "0.488891619",
      "y": "0.858869146"
    },
    {
      "turn": "-0.267949192",
      "x": "0.733337429",
      "y": "0.858869146"
    },
    {
      "turn": "-0.577350269",
      "x": "0.929434573",
      "y": "0.749473094"
    },
    {
      "turn": "0.000000000",
      "x": "0.070565427",
      "y": "0.736646241"
    },
    {
      "turn": "0.247820794",
      "x": "0.307023147",
      "y": "0.713176275"
    },
    {
      "turn": "0.247820794",
      "x": "0.546423600",
      "y": "0.713176275"
    },
    {
      "turn": "-0.288282227",
      "x": "0.426496094",
      "y": "0.638048831"
    },
    {
      "turn": "0.577350269",
      "x": "0.715337424",
      "y": "0.624797843"
    },
    {
      "turn": "-0.000000000",
      "x": "0.856468278",
      "y": "0.628636331"
    },
    {
      "turn": "0.577350269",
      "x": "0.143531722",
      "y": "0.615809478"
    },
    {
      "turn": "0.000000000",
      "x": "0.284662576",
      "y": "0.500499037"
    },
    {
      "turn": "0.000000000",
      "x": "0.644771997",
      "y": "0.502574938"
    },
    {
      "turn": "-0.577350269",
      "x": "0.927033705",
      "y": "0.506413427"
    },
    {
      "turn": "-0.000000000",
      "x": "0.072966295",
      "y": "0.493586573"
    },
    {
      "turn": "0.577350269",
      "x": "0.715337424",
      "y": "0.380352034"
    },
    {
      "turn": "0.000000000",
      "x": "0.856468278",
      "y": "0.384190522"
    },
    {
      "turn": "0.577350269",
      "x": "0.143531722",
      "y": "0.371363669"
    },
    {
      "turn": "0.300993441",
      "x": "0.430796536",
      "y": "0.367498871"
    },
    {
      "turn": "-0.235442031",
      "x": "0.313113461",
      "y": "0.289597576"
    },
    {
      "turn": "-0.235442031",
      "x": "0.549656997",
      "y": "0.289597576"
    },
    {
      "turn": "0.577350269",
      "x": "0.929434573",
      "y": "0.263353759"
    },
    {
      "turn": "0.000000000",
      "x": "0.070565427",
      "y": "0.250526906"
    },
    {
      "turn": "0.267949192",
      "x": "0.266662571",
      "y": "0.141130854"
    },
    {
      "turn": "0.267949192",
      "x": "0.511108381",
      "y": "0.141130854"
    },
    {
      "turn": "0.267949192",
      "x": "0.755554190",
      "y": "0.141130854"
    },
    {
      "turn": "-0.267949192",
      "x": "0.877777095",
      "y": "0.070565427"
    },
    {
      "turn": "-0.267949192",
      "x": "0.144439666",
      "y": "0.070565427"
    },
    {
      "turn": "-0.267949192",
      "x": "0.388885476",
      "y": "0.070565427"
    },
    {
      "turn": "-0.267949192",
      "x": "0.633331285",
      "y": "0.070565427"
    }
  ],
  "radius": "0.141130853"
}
Submission format and technical detailsOpen this when you are ready to prepare a JSON answer+

Instance parameters

{
  "n": 34,
  "sides": 5
}

Starter answer

{
  "placements": [
    {
      "turn": "0.267949192",
      "x": "0.122222905",
      "y": "0.929434573"
    },
    {
      "turn": "0.267949192",
      "x": "0.366668715",
      "y": "0.929434573"
    },
    {
      "turn": "0.267949192",
      "x": "0.611114524",
      "y": "0.929434573"
    },
    {
      "turn": "0.267949192",
      "x": "0.855560334",
      "y": "0.929434573"
    },
    {
      "turn": "-0.267949192",
      "x": "0.244445810",
      "y": "0.858869146"
    },
    {
      "turn": "-0.267949192",
      "x": "0.488891619",
      "y": "0.858869146"
    },
    {
      "turn": "-0.267949192",
      "x": "0.733337429",
      "y": "0.858869146"
    },
    {
      "turn": "-0.577350269",
      "x": "0.929434573",
      "y": "0.749473094"
    },
    {
      "turn": "0.000000000",
      "x": "0.070565427",
      "y": "0.736646241"
    },
    {
      "turn": "0.247820794",
      "x": "0.307023147",
      "y": "0.713176275"
    },
    {
      "turn": "0.247820794",
      "x": "0.546423600",
      "y": "0.713176275"
    },
    {
      "turn": "-0.288282227",
      "x": "0.426496094",
      "y": "0.638048831"
    },
    {
      "turn": "0.577350269",
      "x": "0.715337424",
      "y": "0.624797843"
    },
    {
      "turn": "-0.000000000",
      "x": "0.856468278",
      "y": "0.628636331"
    },
    {
      "turn": "0.577350269",
      "x": "0.143531722",
      "y": "0.615809478"
    },
    {
      "turn": "0.000000000",
      "x": "0.284662576",
      "y": "0.500499037"
    },
    {
      "turn": "0.000000000",
      "x": "0.644771997",
      "y": "0.502574938"
    },
    {
      "turn": "-0.577350269",
      "x": "0.927033705",
      "y": "0.506413427"
    },
    {
      "turn": "-0.000000000",
      "x": "0.072966295",
      "y": "0.493586573"
    },
    {
      "turn": "0.577350269",
      "x": "0.715337424",
      "y": "0.380352034"
    },
    {
      "turn": "0.000000000",
      "x": "0.856468278",
      "y": "0.384190522"
    },
    {
      "turn": "0.577350269",
      "x": "0.143531722",
      "y": "0.371363669"
    },
    {
      "turn": "0.300993441",
      "x": "0.430796536",
      "y": "0.367498871"
    },
    {
      "turn": "-0.235442031",
      "x": "0.313113461",
      "y": "0.289597576"
    },
    {
      "turn": "-0.235442031",
      "x": "0.549656997",
      "y": "0.289597576"
    },
    {
      "turn": "0.577350269",
      "x": "0.929434573",
      "y": "0.263353759"
    },
    {
      "turn": "0.000000000",
      "x": "0.070565427",
      "y": "0.250526906"
    },
    {
      "turn": "0.267949192",
      "x": "0.266662571",
      "y": "0.141130854"
    },
    {
      "turn": "0.267949192",
      "x": "0.511108381",
      "y": "0.141130854"
    },
    {
      "turn": "0.267949192",
      "x": "0.755554190",
      "y": "0.141130854"
    },
    {
      "turn": "-0.267949192",
      "x": "0.877777095",
      "y": "0.070565427"
    },
    {
      "turn": "-0.267949192",
      "x": "0.144439666",
      "y": "0.070565427"
    },
    {
      "turn": "-0.267949192",
      "x": "0.388885476",
      "y": "0.070565427"
    },
    {
      "turn": "-0.267949192",
      "x": "0.633331285",
      "y": "0.070565427"
    }
  ],
  "radius": "0.141130853"
}

Submit {radius, placements:[{x,y,turn},…]}, with each value written as a decimal string of at most nine places. Here x, y are centre coordinates; circles require turn = 0 and polygons use turn = tan(θ/2). Coordinates and turn must lie in [−4, 4], with 0 < radius ≤ 4. · Verifier v1.0.0

DISCUSSION

Discussion

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