P82 · Packing and covering · Classic · Hard

Equal circles in regular polygons · m = 6 · n = 35

Pack n equal circles into the regular m-gon with centre (1,1), circumradius 1, and first vertex (2,1) so as to maximise their common radius.

Instancem = 6 · n = 35
ObjectiveMaximize circle radius

Record comparison

circle radius · Higher is better
RecordValue / intervalAuthor / holderSource
External best known[0.139827762739, 0.139827762741]Eckard SpechtPackomania ↗
Site recordNo player record yet——

Formal definition

  • ContainerThe editor and certificate normalise the container to the exact regular m-gon with centre (1,1), circumradius 1, and first vertex (2,1), while public scores follow the literature convention. 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.
  • ObjectiveMaximise the circle radius r (with container circumradius fixed at 1).
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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. Pentagon and hexagon rows n = 41–100 and octagon rows n = 41–48 cite Packomania's value and author without importing its coordinates; they start from an ordinary site grid baseline.

Source
The current arrangement for Equal circles in regular polygons m = 6 · n = 35
LAYOUT & HISTORY

Starter layout

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ANSWER FORMAT

How to write your answer

the regular m-gon with centre (1,1), circumradius 1, and first vertex (2,1)

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",
      "x": "0.859959353",
      "y": "0.273802359"
    },
    {
      "turn": "0",
      "x": "1.139614878",
      "y": "0.273802359"
    },
    {
      "turn": "0",
      "x": "1.419270404",
      "y": "0.273802359"
    },
    {
      "turn": "0",
      "x": "0.580304795",
      "y": "0.274538137"
    },
    {
      "turn": "0",
      "x": "0.999787115",
      "y": "0.515991148"
    },
    {
      "turn": "0",
      "x": "1.279442641",
      "y": "0.515991148"
    },
    {
      "turn": "0",
      "x": "1.559098166",
      "y": "0.515991148"
    },
    {
      "turn": "0",
      "x": "0.440477032",
      "y": "0.516726926"
    },
    {
      "turn": "0",
      "x": "0.720132558",
      "y": "0.516726926"
    },
    {
      "turn": "0",
      "x": "1.139614878",
      "y": "0.758179938"
    },
    {
      "turn": "0",
      "x": "1.419270404",
      "y": "0.758179938"
    },
    {
      "turn": "0",
      "x": "1.698925929",
      "y": "0.758179938"
    },
    {
      "turn": "0",
      "x": "0.300649270",
      "y": "0.758915715"
    },
    {
      "turn": "0",
      "x": "0.580304795",
      "y": "0.758915715"
    },
    {
      "turn": "0",
      "x": "0.859960321",
      "y": "0.758915715"
    },
    {
      "turn": "0",
      "x": "1.278804955",
      "y": "1.000735778"
    },
    {
      "turn": "0",
      "x": "1.558460480",
      "y": "1.000735778"
    },
    {
      "turn": "0",
      "x": "1.838116006",
      "y": "1.000735778"
    },
    {
      "turn": "0",
      "x": "0.999150397",
      "y": "1.001471555"
    },
    {
      "turn": "0",
      "x": "0.162725958",
      "y": "1.002194101"
    },
    {
      "turn": "0",
      "x": "0.442381483",
      "y": "1.002194101"
    },
    {
      "turn": "0",
      "x": "0.720800500",
      "y": "1.028463175"
    },
    {
      "turn": "0",
      "x": "1.418632717",
      "y": "1.242924567"
    },
    {
      "turn": "0",
      "x": "1.698288243",
      "y": "1.242924567"
    },
    {
      "turn": "0",
      "x": "1.138978160",
      "y": "1.243660345"
    },
    {
      "turn": "0",
      "x": "0.302553721",
      "y": "1.244382891"
    },
    {
      "turn": "0",
      "x": "0.580972737",
      "y": "1.270651964"
    },
    {
      "turn": "0",
      "x": "0.860628262",
      "y": "1.270651964"
    },
    {
      "turn": "0",
      "x": "1.558460480",
      "y": "1.485113356"
    },
    {
      "turn": "0",
      "x": "1.254777680",
      "y": "1.498214237"
    },
    {
      "turn": "0",
      "x": "0.464512914",
      "y": "1.524904442"
    },
    {
      "turn": "0",
      "x": "0.875733024",
      "y": "1.549899273"
    },
    {
      "turn": "0",
      "x": "0.658647561",
      "y": "1.726197641"
    },
    {
      "turn": "0",
      "x": "1.092818487",
      "y": "1.726197641"
    },
    {
      "turn": "0",
      "x": "1.416736874",
      "y": "1.726197641"
    }
  ],
  "radius": "0.139827762"
}
Submission format and technical detailsOpen this when you are ready to prepare a JSON answer+

Instance parameters

{
  "n": 35,
  "sides": 6
}

Starter answer

{
  "placements": [
    {
      "turn": "0",
      "x": "0.859959353",
      "y": "0.273802359"
    },
    {
      "turn": "0",
      "x": "1.139614878",
      "y": "0.273802359"
    },
    {
      "turn": "0",
      "x": "1.419270404",
      "y": "0.273802359"
    },
    {
      "turn": "0",
      "x": "0.580304795",
      "y": "0.274538137"
    },
    {
      "turn": "0",
      "x": "0.999787115",
      "y": "0.515991148"
    },
    {
      "turn": "0",
      "x": "1.279442641",
      "y": "0.515991148"
    },
    {
      "turn": "0",
      "x": "1.559098166",
      "y": "0.515991148"
    },
    {
      "turn": "0",
      "x": "0.440477032",
      "y": "0.516726926"
    },
    {
      "turn": "0",
      "x": "0.720132558",
      "y": "0.516726926"
    },
    {
      "turn": "0",
      "x": "1.139614878",
      "y": "0.758179938"
    },
    {
      "turn": "0",
      "x": "1.419270404",
      "y": "0.758179938"
    },
    {
      "turn": "0",
      "x": "1.698925929",
      "y": "0.758179938"
    },
    {
      "turn": "0",
      "x": "0.300649270",
      "y": "0.758915715"
    },
    {
      "turn": "0",
      "x": "0.580304795",
      "y": "0.758915715"
    },
    {
      "turn": "0",
      "x": "0.859960321",
      "y": "0.758915715"
    },
    {
      "turn": "0",
      "x": "1.278804955",
      "y": "1.000735778"
    },
    {
      "turn": "0",
      "x": "1.558460480",
      "y": "1.000735778"
    },
    {
      "turn": "0",
      "x": "1.838116006",
      "y": "1.000735778"
    },
    {
      "turn": "0",
      "x": "0.999150397",
      "y": "1.001471555"
    },
    {
      "turn": "0",
      "x": "0.162725958",
      "y": "1.002194101"
    },
    {
      "turn": "0",
      "x": "0.442381483",
      "y": "1.002194101"
    },
    {
      "turn": "0",
      "x": "0.720800500",
      "y": "1.028463175"
    },
    {
      "turn": "0",
      "x": "1.418632717",
      "y": "1.242924567"
    },
    {
      "turn": "0",
      "x": "1.698288243",
      "y": "1.242924567"
    },
    {
      "turn": "0",
      "x": "1.138978160",
      "y": "1.243660345"
    },
    {
      "turn": "0",
      "x": "0.302553721",
      "y": "1.244382891"
    },
    {
      "turn": "0",
      "x": "0.580972737",
      "y": "1.270651964"
    },
    {
      "turn": "0",
      "x": "0.860628262",
      "y": "1.270651964"
    },
    {
      "turn": "0",
      "x": "1.558460480",
      "y": "1.485113356"
    },
    {
      "turn": "0",
      "x": "1.254777680",
      "y": "1.498214237"
    },
    {
      "turn": "0",
      "x": "0.464512914",
      "y": "1.524904442"
    },
    {
      "turn": "0",
      "x": "0.875733024",
      "y": "1.549899273"
    },
    {
      "turn": "0",
      "x": "0.658647561",
      "y": "1.726197641"
    },
    {
      "turn": "0",
      "x": "1.092818487",
      "y": "1.726197641"
    },
    {
      "turn": "0",
      "x": "1.416736874",
      "y": "1.726197641"
    }
  ],
  "radius": "0.139827762"
}

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

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