Geometry
See how equal areas survive rotation, reflection, and recombination.
Eastern Puzzle ArchivePuzzle gateway / Tangram
Rebuild the square, then read the geometry.
Tangram is the first full workbench for Eastern Puzzle Archive: a source-backed shape puzzle paired with drag, rotation, snap guidance, hints, and solved-state feedback.
Seven tansDissection geometryPlayable now
Workbench 01 / Tangram
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Hidden mathematics
The same area becomes many shapes.
The first lesson is not calculation. It is seeing that rotation, reflection, and recombination can preserve area while radically changing a silhouette.
State
Treat every valid position as a readable system state, not just a picture.
Source-backed notes
Where the Tangram material begins.
A Short History of the Tangram
The archive begins with the uncertain origin story, overseas spread, and mathematical afterlife of the seven-piece puzzle.
Source pages 25-36View source noteTangram Mathematics
A source-backed path into dissection geometry, topology, graph thinking, and area-preserving transformations.
Source pages 42-96View source note