P85 · Packing and covering · Classic · Hard

Squares in an equilateral triangle · n = 34

Pack n unit squares into an equilateral triangle container with boundary contact allowed and disjoint interiors, minimising the side length of the container triangle.

Instancen = 34
ObjectiveMinimize container triangle side

Record comparison

container triangle side · Lower is better
RecordValue / intervalAuthor / holderSource
External best known[9.618, 9.619)Erich FriedmanErich Friedman ↗
Site recordNo player record yet——

Formal definition

  • ContainerThe editor and certificate normalise the container to the equilateral triangle with vertices (0,0), (1,0), and (1/2,√3/2), 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 triangle side = 1/(2 sin(π/4) r), where smaller is better. Pages, leaderboards, and literature records share this unit with automatic conversion.
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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 Squares in an equilateral triangle n = 34
LAYOUT & HISTORY

Starter layout

Inspect the layout, solver notes and record history.

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ANSWER FORMAT

How to write your answer

the equilateral triangle with vertices (0,0), (1,0), (1/2,√3/2)

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": "0.131652498",
      "x": "0.393093532",
      "y": "0.161042725"
    },
    {
      "turn": "0.131652498",
      "x": "0.273047343",
      "y": "0.161042725"
    },
    {
      "turn": "0.131652498",
      "x": "0.101019630",
      "y": "0.071008083"
    },
    {
      "turn": "-0.131652498",
      "x": "0.450961894",
      "y": "0.639072747"
    },
    {
      "turn": "-0.131652498",
      "x": "0.510984989",
      "y": "0.743035796"
    },
    {
      "turn": "-0.131652498",
      "x": "0.562966513",
      "y": "0.653001155"
    },
    {
      "turn": "-0.131652498",
      "x": "0.614948038",
      "y": "0.562966513"
    },
    {
      "turn": "-0.131652498",
      "x": "0.502943419",
      "y": "0.549038106"
    },
    {
      "turn": "-0.131652498",
      "x": "0.666929562",
      "y": "0.472931872"
    },
    {
      "turn": "-0.131652498",
      "x": "0.554924943",
      "y": "0.459003464"
    },
    {
      "turn": "-0.131652498",
      "x": "0.390938800",
      "y": "0.535109698"
    },
    {
      "turn": "-0.131652498",
      "x": "0.718911087",
      "y": "0.382897230"
    },
    {
      "turn": "-0.131652498",
      "x": "0.606906468",
      "y": "0.368968823"
    },
    {
      "turn": "-0.131652498",
      "x": "0.442920324",
      "y": "0.445075057"
    },
    {
      "turn": "0.131652498",
      "x": "0.308945728",
      "y": "0.431146649"
    },
    {
      "turn": "-0.131652498",
      "x": "0.770892611",
      "y": "0.292862589"
    },
    {
      "turn": "-0.131652498",
      "x": "0.658887992",
      "y": "0.278934181"
    },
    {
      "turn": "0.131652498",
      "x": "0.475086604",
      "y": "0.303058891"
    },
    {
      "turn": "0.131652498",
      "x": "0.377010392",
      "y": "0.341112008"
    },
    {
      "turn": "0.131652498",
      "x": "0.256964204",
      "y": "0.341112008"
    },
    {
      "turn": "-0.414213562",
      "x": "0.827972287",
      "y": "0.155944574"
    },
    {
      "turn": "-0.414213562",
      "x": "0.724009238",
      "y": "0.155944574"
    },
    {
      "turn": "-0.414213562",
      "x": "0.620046189",
      "y": "0.155944574"
    },
    {
      "turn": "-0.414213562",
      "x": "0.516083140",
      "y": "0.155944574"
    },
    {
      "turn": "0.131652498",
      "x": "0.325028868",
      "y": "0.251077366"
    },
    {
      "turn": "0.131652498",
      "x": "0.204982679",
      "y": "0.251077366"
    },
    {
      "turn": "-0.414213562",
      "x": "0.887995381",
      "y": "0.051981525"
    },
    {
      "turn": "-0.414213562",
      "x": "0.784032332",
      "y": "0.051981525"
    },
    {
      "turn": "-0.414213562",
      "x": "0.680069283",
      "y": "0.051981525"
    },
    {
      "turn": "-0.414213562",
      "x": "0.576106234",
      "y": "0.051981525"
    },
    {
      "turn": "-0.414213562",
      "x": "0.472143185",
      "y": "0.051981525"
    },
    {
      "turn": "0.131652498",
      "x": "0.341112008",
      "y": "0.071008083"
    },
    {
      "turn": "0.131652498",
      "x": "0.221065819",
      "y": "0.071008083"
    },
    {
      "turn": "0.131652498",
      "x": "0.153001155",
      "y": "0.161042725"
    }
  ],
  "radius": "0.073512976"
}
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": "0.131652498",
      "x": "0.393093532",
      "y": "0.161042725"
    },
    {
      "turn": "0.131652498",
      "x": "0.273047343",
      "y": "0.161042725"
    },
    {
      "turn": "0.131652498",
      "x": "0.101019630",
      "y": "0.071008083"
    },
    {
      "turn": "-0.131652498",
      "x": "0.450961894",
      "y": "0.639072747"
    },
    {
      "turn": "-0.131652498",
      "x": "0.510984989",
      "y": "0.743035796"
    },
    {
      "turn": "-0.131652498",
      "x": "0.562966513",
      "y": "0.653001155"
    },
    {
      "turn": "-0.131652498",
      "x": "0.614948038",
      "y": "0.562966513"
    },
    {
      "turn": "-0.131652498",
      "x": "0.502943419",
      "y": "0.549038106"
    },
    {
      "turn": "-0.131652498",
      "x": "0.666929562",
      "y": "0.472931872"
    },
    {
      "turn": "-0.131652498",
      "x": "0.554924943",
      "y": "0.459003464"
    },
    {
      "turn": "-0.131652498",
      "x": "0.390938800",
      "y": "0.535109698"
    },
    {
      "turn": "-0.131652498",
      "x": "0.718911087",
      "y": "0.382897230"
    },
    {
      "turn": "-0.131652498",
      "x": "0.606906468",
      "y": "0.368968823"
    },
    {
      "turn": "-0.131652498",
      "x": "0.442920324",
      "y": "0.445075057"
    },
    {
      "turn": "0.131652498",
      "x": "0.308945728",
      "y": "0.431146649"
    },
    {
      "turn": "-0.131652498",
      "x": "0.770892611",
      "y": "0.292862589"
    },
    {
      "turn": "-0.131652498",
      "x": "0.658887992",
      "y": "0.278934181"
    },
    {
      "turn": "0.131652498",
      "x": "0.475086604",
      "y": "0.303058891"
    },
    {
      "turn": "0.131652498",
      "x": "0.377010392",
      "y": "0.341112008"
    },
    {
      "turn": "0.131652498",
      "x": "0.256964204",
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    },
    {
      "turn": "-0.414213562",
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      "y": "0.155944574"
    },
    {
      "turn": "-0.414213562",
      "x": "0.724009238",
      "y": "0.155944574"
    },
    {
      "turn": "-0.414213562",
      "x": "0.620046189",
      "y": "0.155944574"
    },
    {
      "turn": "-0.414213562",
      "x": "0.516083140",
      "y": "0.155944574"
    },
    {
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      "x": "0.325028868",
      "y": "0.251077366"
    },
    {
      "turn": "0.131652498",
      "x": "0.204982679",
      "y": "0.251077366"
    },
    {
      "turn": "-0.414213562",
      "x": "0.887995381",
      "y": "0.051981525"
    },
    {
      "turn": "-0.414213562",
      "x": "0.784032332",
      "y": "0.051981525"
    },
    {
      "turn": "-0.414213562",
      "x": "0.680069283",
      "y": "0.051981525"
    },
    {
      "turn": "-0.414213562",
      "x": "0.576106234",
      "y": "0.051981525"
    },
    {
      "turn": "-0.414213562",
      "x": "0.472143185",
      "y": "0.051981525"
    },
    {
      "turn": "0.131652498",
      "x": "0.341112008",
      "y": "0.071008083"
    },
    {
      "turn": "0.131652498",
      "x": "0.221065819",
      "y": "0.071008083"
    },
    {
      "turn": "0.131652498",
      "x": "0.153001155",
      "y": "0.161042725"
    }
  ],
  "radius": "0.073512976"
}

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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