Curiosities and Questions

• Ancestors Problem     (Post)
• Corner Reflectors     (Post)
• Degree of Latitude     (Post)
• Earth as Magnet     (Post)
• Escalator Terror     (Post)
• Exponential Yarn     (Post)
• February 29     (Post)
• Logical Dead End     (Post)
• Microwave Problem     (Post)
• Nahin Triangle Problem     (Post)
• Noah and Population Growth     (Post)
• Percentage Trap     (Post)
• Pythagorean Theorem     (Post)
• Pythagorean Theorem Converse     (Post)
• Slow Lane Problem     (Post)
• South Dakota Travel Problem     (Post)
• Strange Statistics     (Post)
• Three Jugs Problem     (Post)
• Train Wreck Puzzle     (Post)
• Tupper Self-Referential Formula     (Post)
• Vitruvian Man Problem     (Post)

Puzzles and Problems

Geometry Puzzles

• 15 Degree Triangle Puzzle     (Post)
• Amazing Triangle Problem     (Post)
• Another Cube Slice Problem     (Post)
• Another Octagonal Area Problem     (Post)
• Ant Connection Problem     (Post)
• Area vs. Perimeter Puzzle     (Post)
• Broken Diagonal Problem     (Post)
• Center of Square Problem     (Post)
• Chalkdust Triangle Problem     (Post)
• Challenging Triangle Problem     (Post)
• Chord Progression Puzzle     (Post)
• Circle Chord Problem     (Post)
• Circle-Halving Zigzag Problem     (Post)
• Circle in Slot Problem     (Post)
• Circle Projection Problem     (Post)
• Circle Tangent Chord Problem     (Post)
• Circles in Circles     (Post)
• Circular Rendezvous Mystery     (Post)
• Circumscribed House Problem     (Post)
• Classic Geometry Paradox     (Post)
• Containing an Arc     (Post)
• Covering Rectangle Puzzle     (Post)
• Cube Slice Angle Problem     (Post)
• Curve Making Puzzle     (Post)
• Diabolical Triangle Puzzle     (Post)
• Distance to Flag Problem     (Post)
• Elliptical Medians Problem     (Post)
• Envelope Puzzle     (Post)
• Equitable Slice Problem     (Post)
• Floating Square Puzzle    (Post)
• Four of a Kind     (Post)
• Hard Geometric Problem     (Post)
• Hjelmslev’s Theorem     (Post)
• An Intercept Problem     (Post)
• Keyhole Problem     (Post)
• Ladder Locus Puzzle     (Post)
• Leaning Squares     (Post)
• Line Work     (Post)
• Linked Triangles Problem     (Post)
• Lop-sided Hexagon Problem     (Post)
• Magic Hexagons     (Post)
• Magic Parallelogram     (Post)
• Max Angle Puzzle     (Post)
• Missing Interval Puzzle     (Post)
• Modern Art     (Post)
• Moon Quarters Problem     (Post)
• More Right Triangle Magic     (Post)
• More Squares in Semicircle     (Post)
• More Sum of Angles     (Post)
• Mysterious Doppelgänger Problem     (Post)
• Neuberg’s Theorem     (Post)
• Nested Polygons Puzzle     (Post)
• Octagonal Area Problem     (Post)
• Parallel Lines Problem     (Post)
• Parallelogram Cosine Problem     (Post)
• Parallelogram Puzzle     (Post)
• Perimeter-Area Problem     (Post)
• Pillar Wrapping Problem     (Post)
• Pinwheel Area Problem     (Post)
• Playing with Triangles     (Post)
• Polygon Altitude Problems I     (Post)
• Polygon Altitude Problems II     (Post)
• Polygon Areas Problem     (Post)
• Polygon Rings     (Post)
• Pool Paving Problem     (Post)
• Putnam Ellipse Areas Problem     (Post)
• Putnam Octagon Problem     (Post)
• Pythagorean Parabola Puzzle     (Post)
• Quad in Circle Problem     (Post)
• Quadrangle in Parallelogram     (Post)
• Red Star     (Post)
• Regiomontanus 1471 Problem     (Post)
• Right Angles in a Square     (Post)
• Right Triangle with Roots     (Post)
• Rising Sun     (Post)
• River Crossing     (Post)
• Road Construction Problem    (Post)
• Rolling Wheels Puzzle     (Post)
• Shy Angle Problem     (Post)
• Six Squares Problem     (Post)
• Sizing Up     (Post)
• Snooker Puzzle     (Post)
• Sphere and Plane Puzzle     (Post)
• Spiral Areas Puzzle     (Post)
• Square Deal     (Post)
• Square in Quarter Circle     (Post)
• Square Root Minimum     (Post)
• String of Beads Puzzle     (Post)
• Star Polygon Problem     (Post)
• Star Sum of Angles     (Post)
• Sum of Squares Puzzle     (Post)
• Tandem Circles     (Post)
• Tethered Triangle Puzzle     (Post)
• Thoth Maneuver     (Post)
• Three Coffin Problems     (Post)
• Three Equal Circles     (Post)
• Three Triangles Puzzle     (Post)
• A Tidy Theorem     (Post)
• Tipsy 3-4-5 Triangle     (Post)
• Topple Blocks Puzzle     (Post)
• Triangle Acute-Angle Problem     (Post)
• Triangle of Abū’l-Wafā’     (Post)
• Triangle Puzzle     (Post)
• Triangle Projection Problem     (Post)
• Triangle Quadrangle Puzzle     (Post)
• Triangle Stripes Problem     (Post)
• Triangular Boundary Problem     (Post)
• Turning Wheels Puzzle     (Post)
• Twin Intersection Puzzle     (Post)
• Twisting Beam Problem     (Post)
• Two and a Half Circles     (Post)
• Two Circles Puzzle     (Post)
• Two Curious Semicircles     (Post)
• Two Equilateral Triangles     (Post)
• Two Squares Problem     (Post)
• Ubiquitous Radius Problem     (Post)
• Vector Sum Problem     (Post)
• Wandering Epicycle     (Post)
• Wisdom of Old     (Post)

Catriona Agg (nee Shearer) Geometry Puzzles

• Cascading Squares Problem     (Post)
• Curious Sunbeam Problem     (Post)
• Geometric Puzzle Madness     (Post)
• Geometric Puzzle Magic     (Post)
• Geometric Puzzle Magnificence     (Post)
• Geometric Puzzle Marvels     (Post)
• Geometric Puzzle Mayhem     (Post)
• Geometric Puzzle Meditations     (Post)
• Geometric Puzzle Medley     (Post)
• Geometric Puzzle Mindbogglers     (Post)
• Geometric Puzzle Munificence     (Post)
• Geometric Puzzle Mystifiers     (Post)
• Hexagon-Rectangle Problem     (Post)
• Kissing Angles     (Post)
• Parallelogram Problem     (Post)
• Two Block Incline Puzzle     (Post)

Travel Puzzles

• Air Travel     (Post)
• Bicycle Problem     (Post)
• Bixley to Quixley Puzzle     (Post)
• Calculating on the Way     (Post)
• Catching the Thief     (Post)
• Close Race Puzzle     (Post)
• Damaged Engine     (Post)
• Escalator Puzzle     (Post)
• Four Travelers Problem     (Post)
• Handicap Racing     (Post)
• Horses to Qi     (Post)
• The Hose Knows     (Post)
• Impossible Car Riddle     (Post)
• Locating the Loot     (Post)
• Marching Cadets and Dog Problem     (Post)
• Meeting on the Bridge     (Post)
• Mountain Climbing Puzzle     (Post)
• Moving Up     (Post)
• Old Hook Puzzle     (Post)
• Parallel Stroll Problem     (Post)
• Perpetual Meetings Problem     (Post)
• River Traffic Problem     (Post)
• Rufus Puzzle     (Post)
• Skating Rendezvous Problem     (Post)
• Storm Chaser Problem     (Post)
• Tandem Bicycle Puzzle     (Post)
• Three Runners Puzzle     (Post)
• Timing the Car     (Post)
• Track Problem     (Post)
• Train Buffs     (Post)
• Train Length Puzzle     (Post)
• Trains – Pickleminster to Quickville     (Post)
• Tree Trunk Puzzle     (Post)
• Turnpike Driving     (Post)
• Two Errand Boys     (Post)
• Two Trains – London to Liverpool     (Post)
• Two Trains – Passing in the Night     (Post)
• Walking Banker Problem     (Post)
• Yet Another Race     (Post)

Logic Puzzles

• Box Code Puzzle     (Post)
• Blockbusters Problem     (Post)
• Date Night     (Post)
• Do I Avoid Kangaroos?     (Post)
• Fermat’s Last Theorem Puzzle     (Post)
• Heron Suit Problem     (Post)
• Logical Dead End     (Post)
• The Maths of Lviv     (Post)
• The Mystery of the Dancing Men     (Post)
• Numbers in New Guinea     (Post)
• Peirce’s Law     (Post)
• Pinocchio’s Hats     (Post)
• Pointing Fingers     (Post)
• Purloined Papers Puzzle     (Post)
• Rock Paper Scissors Problem     (Post)
• Shared Spaces Puzzle     (Post)
• Squirrel Puzzle     (Post)
• Swallowing Elephants     (Post)
• Who Did It?     (Post)

Clock Puzzles

• After Five O’Clock     (Post)
• Clock Connections Puzzle     (Post)
• Fallen Clock Puzzle     (Post)
• Grandfather Clock Puzzle     (Post)
• Hard Time Conundrum     (Post)
• A Question of Time     (Post)

Mixture Problems

• Al the Chemist II     (Post)
• Diluted Wine Puzzle     (Post)
• Milk Mixing Puzzle     (Post)
• Three Jugs Problem     (Post)
• Three Jugs Problem Redux     (Post)
• Two Containers Mixing Puzzle     (Post)
• Two More Jugs     (Post)
• Two Pints of Cider     (Post)
• Weight of Potatoes     (Post)
• Wine Into Water Problem     (Post)

Work Problems

• Alcan Highway Problem     (Post)
• Bailing Water Problem     (Post)
• Fibonacci, Chickens, and Proportions     (Post)
• Making Arrows     (Post)
• Refabulating Widgets     (Post)

Algebra and Other Puzzles

• 1770 Card Game Problem     (Post)
• Additional Page Problem     (Post)
• Al the Chemist I     (Post)
• Alcuin’s Corn Problem     (Post)
• Amazing Radical Sum     (Post)
• Ant Problem     (Post)
• Barrel of Beer     (Post)
• Barrier Minimal Path Problem     (Post)
• Butcher Boy Problem     (Post)
• Chalkdust Grid Problem     (Post)
• Challenging Sum     (Post)
• Christmas Tree Puzzle     (Post)
• Consecutive Product Square     (Post)
• Counterfeit Coin in Base 3     (Post)
• Cube Roots Problem     (Post)
• Factory Location Problem     (Post)
• Falling Sound Problem     (Post)
• Family Values     (Post)
• Fashion Puzzle     (Post)
• Hitting the Target     (Post)
• Ladies’ Diary Problem     (Post)
• Language Students Puzzle     (Post)
• Log Jam     (Post)
• Log Lunacy     (Post)
• Loggers Problem     (Post)
• Lucky 7 Problem     (Post)
• Maximized Box Problem     (Post)
• Missing Pages Puzzle     (Post)
• MoMath Mazes     (Post)
• More Pool     (Post)
• Mountain Houses Problem     (Post)
• Movie Projector Problem     (Post)
• Mr. Gubbins in a Fog     (Post)
• A Multitude of 2s     (Post)
• Mystery Dice Question     (Post)
• Mystery Number Puzzle     (Post)
• Mystery Quadratic     (Post)
• Painting Lampposts     (Post)
• Passion Kiss Problem     (Post)
• Pearl Necklace Problem     (Post)
• Pole Leveling Puzzle     (Post)
• Pool Party     (Post)
• Power of 2 Problem     (Post)
• Quintic Nightmare     (Post)
• Radical Radicals     (Post)
• Railroad Tie Problem     (Post)
• Rubber Band Ant     (Post)
• Seven Girls Puzzle     (Post)
• Simple Polynomial Puzzle     (Post)
• Spy Gift Problem     (Post)
• Staircase Race     (Post)
• Table Tabby Tortoise Problem     (Post)
• Three Counting Puzzles     (Post)
• Three Dutchmen Puzzle     (Post)
• Threewise Problem     (Post)
• A Tricky Product     (Post)
• Tricky Ratio Puzzle     (Post)
• Two Candles     (Post)
• Umbrella Problem     (Post)
• Young and Old Problem     (Post)
• Weight Problem of Bachet     (Post)

Math Inquiries

• Alberti’s Perspective Construction     (Post)
• Amazing Identity     (Post)
• Amazing Root Problem     (Post)
• Another Christmas Tree Puzzle     (Post)
• Bottema’s Theorem     (Post)
• Bugles, Trumpets, and Beltrami     (Post)
• Complex Numbers – Geometric Viewpoint     (Post)
• Conical Bottle Problem     (Post)
• Cutting Elliptical Pizza     (Post)
• Elliptic Circles     (Post)
• Euler Magic     (Post)
• Existence Proofs     (Post)
• Existence Proofs II     (Post)
• Fibonacci, Chickens, and Proportions     (Post)
• Fireworks Rocket     (Post)
• Flipping Parabolas     (Post)
• Hossenfelder Stagnation Problem     (Post)
• Hyperboloid as Ruled Surface     (Post)
• Kepler’s Ellipse     (Post)
• Kepler’s Equal Areas Law     (Post)
• Kepler’s Laws and Newton’s Laws     (Post)
• Lambert Equal Area Projection     (Post)
• Logging Problem     (Post)
• Lorentz Transformation     (Post)
• Magic Pythagorean Circle     (Post)
• Math and Religion     (Post)
• Maximum Product     (Post)
• Mercator Projection Balloon     (Post)
• Minimum Path Via Circle     (Post)
• Pairwise Products     (Post)
• Perspective Map     (Post)
• Playing with Polys     (Post)
• Point of Intersection Problem     (Post)
• Point Set Topology     (Post)
• Polynomial Division Problem     (Post)
• Power of 2 Problem     (Post)
• Remainder Problem     (Post)
• Root Difference     (Post)
• Rotating Plane Problem     (Post)
• Self-Characterizing Figure     (Post)
• Square Wheels     (Post)
• Straight and Narrow Problem     (Post)
• Tired Messenger Problem     (Post)

Sequences and Series

• Another Challenging Sum     (Post)
• Autumn Sum     (Post)
• Fibonacci Fandango     (Post)
• Incredible Trick Puzzle     (Post)
• Infinite Product Problem     (Post)
• New Years Sum     (Post)
• Nice Factorial Sum     (Post)
• Number of the Beast     (Post)
• Serious Series     (Post)
• Special Log Sum     (Post)
• Stimulating Sequence     (Post)
• Surprising Identity     (Post)
• Unexpected Sum     (Post)
• Winter Sum     (Post)

Math Commentary

• Angular Momentum     (Post)
• Down With Geometry     (Post)
• Essence of Mathematics     (Post)
• Learning Mathematics     (Post)
• Lure of Mathematics Conundrum     (Post)
• Meditation on “Is” in Mathematics I – Zeno’s Paradox     (Post)
• Meditation on “Is” in Mathematics II – Mathematical Reality     (Post)
• Meditation on “Is” in Mathematics III – Heliocentrism     (Post)
• Newton and Declaration of Independence     (Post)
• Restructuring the US Senate     (Post)
• Za’irajah and Mathematics     (Post)

Other Voices

• Abraham Lincoln Technologist     (Post)
• Aesthetic Curiosity – The Root of Invention     (Post)
• Apocalypse Math     (Post)
• Aunt Hillary and the Anteater     (Post)
• Bourbaki World     (Post)
• Coronavirus Mathematics     (Post)
• Counting Tanks     (Post)
• Danica McKellar Interview     (Post)
• A Divine Language     (Post)
• Gerrymandering at SCOTUS     (Post)
• Math and Literature     (Post)
• Math and the Excellence of Life     (Post)
• A Mathematician in the Jury Box     (Post)
• A New Day     (Post)
• Newton and Declaration of Independence     (Post)
• Physical, Mathematical, Personal Reality     (Post)
• Profession of Engineering    (Post)
• Survival of Records (58 MB), Survival of Records wo figs (700 KB)     (Post)
• Who Gets To Be Called A Mathematician     (Post)

Other Vistas

• Happy Day     (Post)
• Reductio ad Absurdum    (Post)
• A Voice From the Past     (Post)
• Voice Stealing     (Post)
• Vote     (Post)

Causality, Chance, and Connections

• Causality, Chance, and Connections     (Post)
• Chemical Determinism – Motor Proteins     (Post)
• Columbus and the Irony of Chance     (Post)
• Greek-Indian Connection     (Post)
• Symbolic Algebra Timelines     (Post)
• Turkey Red (Ukraine)     (Post)

Administration

• Feedback Request     (Post)
• One Year Anniversary     (Post)
• Two Year Anniversary     (Post)
• Three Year Anniversary     (Post)
• Four Year Anniversary     (Post)
• Five Year Anniversary     (Post)