Puzzle #5
Two squares meet at the center/centre of a circle. The yellow square has area 20.
What is the area of the red square?
This puzzle was published on @theguardian.com.
Check the solution in the comments.
#math #geometry #puzzle #mathsky
Happy Pi Day!
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My upcoming book ๐๐๐ฌ๐ญ๐๐ซ๐ข๐ง๐ ๐๐๐จ๐ฆ๐๐ญ๐ซ๐ฒ ๐๐ฎ๐ณ๐ณ๐ฅ๐๐ฌ is already #1 New Release in Geometry and Topology.
You can pre-order it on Amazon ๐
www.amazon.com/Mastering-Ge...
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They cannot be removed, only moved.
Puzzle #4
The area of the isosceles triangle is 108. The dots separe the sides in equal parts.
What is the area of the kite?
Check the solution in the comments.
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(9/9) A warning: these puzzles can lead to a serious puzzle addiction! Enjoy the challenge!
You can pre-order it on Amazon or any bookstore around the World. There are paperback, hardcover and Kindle versions available.
(8/9) All the puzzles have step-by-step solutions. The puzzles can be solved by geometry puzzle lovers of all ages. The puzzler does not need to be an ace in geometry to solve them.
(7/9) The information given to solve the puzzle should be as minimal as possible, sometimes to the point that the reader might think that it is not possible to solve it. This is part of the challenge of puzzles.
(6/9) Puzzles should not only be fun in their design, but they should also be fun to solve. Their shape should be appealing to arouse curiosity in the reader.
(5/9) The first chapter, Solving a Puzzle, offers a typical puzzle, which then is solved step-by-step. It presents how geometry is used to solve it, and the logical thinking leading to the solution.
(4/9) There are three types of geometry puzzles in this book:
โข No shape-based puzzles, i.e., triangles, circles, etc.
โข General shape-based puzzles, i.e., a hamburger, a bird, etc.
โข Japanese shape-based puzzles, i.e., a samurai, a bonsai, etc.
(3/9) Even if mathematical puzzles are new to the reader, this book is a great place to start. Puzzle solving is not only fun; it will also enhance the reader's understanding of mathematics. More experienced puzzlers will also find very challenging opportunities.
(2/9) This book will challenge mathematical skills in a totally different way from the usual geometric puzzles. These 120 puzzles are visually intriguing. Mastering Geometry Puzzles has 5 chapters of puzzles, each one corresponding to a level of difficulty, from the very easy to the very hard.
(1/9) My new book ๐๐๐ฌ๐ญ๐๐ซ๐ข๐ง๐ ๐๐๐จ๐ฆ๐๐ญ๐ซ๐ฒ ๐๐ฎ๐ณ๐ณ๐ฅ๐๐ฌ will be released on April 9, 2026.
You can pre-order it on Amazon ๐
www.amazon.com/Mastering-Ge...
Learn more about it in the comments.
#math #geometry #puzzle #book #MasteringGeometryPuzzles #booksky
Puzzle #3
The figure is created out of twelve matchsticks.
Modify the position of four matchsticks to get two squares.
Check the solution in the comments.
#math #matchstick #puzzle #mathsky
Puzzle #2
The number 403 is created out of fifteen matchsticks.
Modify the position of two matchsticks to get a number divisible by 9.
This puzzle was published on @nytimes.com and on @theguardian.com.
Check the solution in the comments.
#math #matchstick #puzzle #mathsky
My new book ๐๐๐ฌ๐ญ๐๐ซ๐ข๐ง๐ ๐๐๐จ๐ฆ๐๐ญ๐ซ๐ฒ ๐๐ฎ๐ณ๐ณ๐ฅ๐๐ฌ will be released on April 9, 2026.
The book contains 120 geometry puzzles divided into 5 difficulty levels, from the very easy to the very hard. Each puzzle has a step-by-step solution.
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It is a link to my blog where you can find the solution.
Puzzle #1
The isosceles trapezoid/trapezium is composed of seven matchsticks.
Modify the position of three matchsticks to get two equilateral triangles.
This puzzle was published on @nctm.org and on @theguardian.com.
Check the solution in the comments.
#math #matchstick #puzzle #mathsky
My new book ๐๐๐ฌ๐ญ๐๐ซ๐ข๐ง๐ ๐๐๐จ๐ฆ๐๐ญ๐ซ๐ฒ ๐๐ฎ๐ณ๐ณ๐ฅ๐๐ฌ will be released on April 9, 2026.
Pre-orders will begin on March 19, 2026.
Stay tuned for more news about it soon.
#math #geometry #puzzle #book #MasteringGeometryPuzzles #mathsky #booksky
