72 Sangaku Problems

• Sangaku: Reflections on the Phenomenon
• Critique of My View and a Response
• 1 + 27 = 12 + 16 Sangaku

• 3-4-5 Triangle by a Kid
• 7 = 2 + 5 Sangaku
• A 49th Degree Challenge
• A Geometric Mean Sangaku
• A Hard but Important Sangaku
• A Restored Sangaku ProblemA better solution to a difficult sangaku problem
• A Simple Solution to a Difficult Sangaku Problem
• A Trigonometric Solution to a Difficult Sangaku Problem
• A Sangaku: Two Unrelated Circles
• A Sangaku by a Teen
• A Sangaku Follow-Up on an Archimedes' Lemma
• A Sangaku with an Egyptian Attachment
• A Sangaku with Many Circles and Some
• A Sushi Morsel
• An Old Japanese Theorem
• Archimedes Twins in the Edo Period
• Arithmetic Mean Sangaku
• Bottema Shatters Japan's Seclusion
• Chain of Circles on a Chord
• Circles and Semicircles in Rectangle
• Circles in a Circular Segment
• Circles Lined on the Legs of a Right Triangle
• Equal Incircles TheoremEqual Incircle Theorem, Angela Drei's Proof
• Equilateral Triangle, Straight Line and Tangent Circles
• Equilateral Triangles and Incircles in a Square
• Five Incircles in a Square
• Four Hinged Squares
• Four Incircles in Equilateral TriangleFour Incircles in an Equilateral Triangle, a Sangaku
• Gion Shrine Problem
• Harmonic Mean Sangaku
• Heron's Problem
• In the Wasan Spirit
• Incenters in Cyclic Quadrilateral
• Japanese Art and Mathematics
• Malfatti's Problem
• Maximal Properties of the Pythagorean Relation
• Neuberg Sangaku
• Out of Pentagon Sangaku
• Peacock Tail Sangaku
• Pentagon Proportions Sangaku
• Proportions in Square
• Pythagoras and Vecten Break Japan's Isolation
• Radius of a Circle by Paper Folding
• Review of Sacred Mathematics
• Sangaku à la V. Thebault
• Sangaku and The Egyptian Triangle
• Sangaku in a Square
• Sangaku Iterations, Is it Wasan?
• Sangaku with 8 Circles
• Sangaku with Angle between a Tangent and a Chord
• Sangaku with Quadratic Optimization
• Sangaku with Three Mixtilinear Circles
• Sangaku with Versines
• Sangakus with a Mixtilinear Circle
• Sequences of Touching Circles
• Square and Circle in a Gothic Cupola
• Steiner's Sangaku
• Tangent Circles and an Isosceles Triangle
• The Squinting Eyes Theorem
• Three Incircles In a Right Triangle
• Three Squares and Two Ellipses
• Three Tangent Circles SangakuAn Extension of a Sangaku with Touching Circles
• Triangles, Squares and Areas from Temple Geometry
• Two Arbelos, Two Chains
• Two Circles in an Angle
• Two Sangaku with Equal Incircles
• Another Sangaku in Square
• Sangaku via Peru
• FJG Capitan's Sangaku