P85 · Packing and covering · Classic · Hard

Squares in an equilateral triangle · n = 32

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 = 32
ObjectiveMinimize container triangle side

Record comparison

container triangle side · Lower is better
RecordValue / intervalAuthor / holderSource
External best known[9.464, 9.465)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 = 32
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": "0.488835450",
      "y": "0.741025404"
    },
    {
      "turn": "0.131652498",
      "x": "0.436004234",
      "y": "0.649519053"
    },
    {
      "turn": "-0.131652498",
      "x": "0.572168784",
      "y": "0.635362971"
    },
    {
      "turn": "0.131652498",
      "x": "0.384960492",
      "y": "0.556980703"
    },
    {
      "turn": "-0.131652498",
      "x": "0.624022072",
      "y": "0.543292013"
    },
    {
      "turn": "0.414213562",
      "x": "0.492805755",
      "y": "0.478417266"
    },
    {
      "turn": "0.131652498",
      "x": "0.331443080",
      "y": "0.465870528"
    },
    {
      "turn": "-0.131652498",
      "x": "0.676665673",
      "y": "0.451677343"
    },
    {
      "turn": "0.131652498",
      "x": "0.278951474",
      "y": "0.374168102"
    },
    {
      "turn": "0.414221741",
      "x": "0.438046237",
      "y": "0.372340505"
    },
    {
      "turn": "0.414221741",
      "x": "0.543968144",
      "y": "0.372341967"
    },
    {
      "turn": "-0.131652498",
      "x": "0.729532220",
      "y": "0.360191390"
    },
    {
      "turn": "0.131652498",
      "x": "0.224679369",
      "y": "0.283493649"
    },
    {
      "turn": "-0.131652498",
      "x": "0.783493649",
      "y": "0.269337567"
    },
    {
      "turn": "0.414213562",
      "x": "0.386164550",
      "y": "0.266417858"
    },
    {
      "turn": "0.414221384",
      "x": "0.492003073",
      "y": "0.266419348"
    },
    {
      "turn": "0.414221744",
      "x": "0.597924984",
      "y": "0.266420810"
    },
    {
      "turn": "-0.131652498",
      "x": "0.836324865",
      "y": "0.177831216"
    },
    {
      "turn": "0.414213562",
      "x": "0.174839684",
      "y": "0.158493649"
    },
    {
      "turn": "0.414213562",
      "x": "0.280502117",
      "y": "0.158493649"
    },
    {
      "turn": "0.414213562",
      "x": "0.386164550",
      "y": "0.160495947"
    },
    {
      "turn": "0.414213562",
      "x": "0.491826982",
      "y": "0.160497413"
    },
    {
      "turn": "0.414213562",
      "x": "0.597489415",
      "y": "0.160498899"
    },
    {
      "turn": "0.414213562",
      "x": "0.703151848",
      "y": "0.158493649"
    },
    {
      "turn": "0.414213562",
      "x": "0.113835450",
      "y": "0.052831216"
    },
    {
      "turn": "0.414213562",
      "x": "0.219510220",
      "y": "0.052831216"
    },
    {
      "turn": "0.414213562",
      "x": "0.325172657",
      "y": "0.052831216"
    },
    {
      "turn": "0.414213600",
      "x": "0.430844144",
      "y": "0.053956835"
    },
    {
      "turn": "0.414213562",
      "x": "0.536589669",
      "y": "0.053956835"
    },
    {
      "turn": "0.414213562",
      "x": "0.642279524",
      "y": "0.052831216"
    },
    {
      "turn": "0.414213562",
      "x": "0.748201439",
      "y": "0.052831216"
    },
    {
      "turn": "0.414213562",
      "x": "0.854123350",
      "y": "0.052831216"
    }
  ],
  "radius": "0.074714622"
}
Submission format and technical detailsOpen this when you are ready to prepare a JSON answer+

Instance parameters

{
  "n": 32,
  "sides": 5
}

Starter answer

{
  "placements": [
    {
      "turn": "0.131652498",
      "x": "0.488835450",
      "y": "0.741025404"
    },
    {
      "turn": "0.131652498",
      "x": "0.436004234",
      "y": "0.649519053"
    },
    {
      "turn": "-0.131652498",
      "x": "0.572168784",
      "y": "0.635362971"
    },
    {
      "turn": "0.131652498",
      "x": "0.384960492",
      "y": "0.556980703"
    },
    {
      "turn": "-0.131652498",
      "x": "0.624022072",
      "y": "0.543292013"
    },
    {
      "turn": "0.414213562",
      "x": "0.492805755",
      "y": "0.478417266"
    },
    {
      "turn": "0.131652498",
      "x": "0.331443080",
      "y": "0.465870528"
    },
    {
      "turn": "-0.131652498",
      "x": "0.676665673",
      "y": "0.451677343"
    },
    {
      "turn": "0.131652498",
      "x": "0.278951474",
      "y": "0.374168102"
    },
    {
      "turn": "0.414221741",
      "x": "0.438046237",
      "y": "0.372340505"
    },
    {
      "turn": "0.414221741",
      "x": "0.543968144",
      "y": "0.372341967"
    },
    {
      "turn": "-0.131652498",
      "x": "0.729532220",
      "y": "0.360191390"
    },
    {
      "turn": "0.131652498",
      "x": "0.224679369",
      "y": "0.283493649"
    },
    {
      "turn": "-0.131652498",
      "x": "0.783493649",
      "y": "0.269337567"
    },
    {
      "turn": "0.414213562",
      "x": "0.386164550",
      "y": "0.266417858"
    },
    {
      "turn": "0.414221384",
      "x": "0.492003073",
      "y": "0.266419348"
    },
    {
      "turn": "0.414221744",
      "x": "0.597924984",
      "y": "0.266420810"
    },
    {
      "turn": "-0.131652498",
      "x": "0.836324865",
      "y": "0.177831216"
    },
    {
      "turn": "0.414213562",
      "x": "0.174839684",
      "y": "0.158493649"
    },
    {
      "turn": "0.414213562",
      "x": "0.280502117",
      "y": "0.158493649"
    },
    {
      "turn": "0.414213562",
      "x": "0.386164550",
      "y": "0.160495947"
    },
    {
      "turn": "0.414213562",
      "x": "0.491826982",
      "y": "0.160497413"
    },
    {
      "turn": "0.414213562",
      "x": "0.597489415",
      "y": "0.160498899"
    },
    {
      "turn": "0.414213562",
      "x": "0.703151848",
      "y": "0.158493649"
    },
    {
      "turn": "0.414213562",
      "x": "0.113835450",
      "y": "0.052831216"
    },
    {
      "turn": "0.414213562",
      "x": "0.219510220",
      "y": "0.052831216"
    },
    {
      "turn": "0.414213562",
      "x": "0.325172657",
      "y": "0.052831216"
    },
    {
      "turn": "0.414213600",
      "x": "0.430844144",
      "y": "0.053956835"
    },
    {
      "turn": "0.414213562",
      "x": "0.536589669",
      "y": "0.053956835"
    },
    {
      "turn": "0.414213562",
      "x": "0.642279524",
      "y": "0.052831216"
    },
    {
      "turn": "0.414213562",
      "x": "0.748201439",
      "y": "0.052831216"
    },
    {
      "turn": "0.414213562",
      "x": "0.854123350",
      "y": "0.052831216"
    }
  ],
  "radius": "0.074714622"
}

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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