About
The scope of this collection
This page records the mathematical purpose and editorial principles of the collection.
Elementary Geometry is a growing collection of problems, proofs, and diagrams. Its central concern is the structure of classical Euclidean geometry: how a configuration becomes intelligible through a well-chosen construction, transformation, invariant, or representation.
The subject is classical Euclidean geometry; the method is chosen according to what makes the structure visible.
The collection favours arguments that can be reused, alternative proofs that reveal different features of a figure, and diagrams precise enough to support the mathematics rather than merely decorate it.
The classical theorem notes revisit familiar results and trace the further structures revealed by each method. The drawing process is treated as part of the mathematical exposition.
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Public pages distinguish statements, observations, proofs, and interpretations.
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Sources and publication status are recorded without guessing missing bibliographic data.
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Unpublished original work and private drafts are not placed in the public repository.
Classical Geometry develops the configurations;Methods supplies the supporting language and formulas.Problems distinguishes original problems from selected solutions, while Diagrams connects figures, articles, and drawing sources.
About the author
Chikara Tsugawa studied algebra as an undergraduate and completed a master’s degree with a focus on algebraic geometry. He then began a career in finance in Japan and has continued to study mathematics independently.
His interests include classical Euclidean geometry, olympiad-style problem solving, and the ways in which different methods reveal different features of a geometric configuration. Several of his solutions and observations have appeared in Crux Mathematicorum, and he has also proposed problems for the journal.
Contact
For comments, corrections, or correspondence concerning the articles on this site, please write to contact@elementarygeometry.org.