Prologue: Why Euclidean Geometry?
The History of Mathematics│The Fun of Euclidean Geometry│Logical and Creative Thinking

Part 1: Minimum Knowledge for the Biggest Idea

Chapter 1: Confidence is the foundation
Confidence and a positive attitude are required. │ Be proactive and proactive. │ Stimulate imagination. │ Imagine what it would be like to be a teacher.
Chapter 2: The Great and Absolute Proof of Euclidean Geometry
The mathematical tradition established by Euclid, proof│Euclid's axioms
Chapter 3: The Beginning of Geometry: Similarity and Congruence
Thales, the world's first mathematician | How to use similarity and congruence | How Thales calculated the height of the pyramid
Chapter 4 The Simplest Shape, the Triangle
Find the area of ​​a triangle│Understanding comes before calculation
Chapter 5: The Key to Problem Solving: Isosceles Triangles
A triangle with two sides and two angles of equal length│Isosceles triangle properties you must remember│Creating an isosceles triangle at will
Chapter 6: The Core of Area Problems, Squares
What is the Area of ​​a Shape? │Four Quadrilaterals Needed for Problem Solving
Chapter 7: The Perfect Shape, the Circle
Those who do not know geometry, please do not enter│Archimedes, who calculated pi 2,200 years ago│A circle with perfect symmetry│When a circle and a line intersect│Drawing a line from a point to a circle│Central angle and central angle│Triangles and quadrilaterals inscribed in a circle

Part 2: Euclidean Thinking for Finding Ideas

Chapter 8 Thinking in Ratios
Rational Numbers│Finding Familiar Ratios
Chapter 9: Thinking in Divide
Dividing What You Don't Know into What You Know│The Answer Is Revealed When You Divide
Chapter 10: Finding Known Shapes
Starting from the Familiar│Finding Within the Problem
Chapter 11: Finding Where to Apply Familiar Formulas
The most important mathematical formula│Similarity of shapes and the Pythagorean theorem│Various ways to prove the Pythagorean theorem│Proving with geometry, not calculation
Chapter 12: Finding Special Right Triangles
Two Special Right Triangles│Using the Area of ​​an Equilateral Triangle│Finding Special Right Triangles│Circles and Right Triangles
Chapter 13: Calculating and Imagining
Don't just calculate blindly│Imagination is blocked when concepts and calculations come first│How to be good at both calculation and imagination

Part 3: Problem-Solving Techniques that Break the Frame of Answers

Chapter 14: The Art of Tricks
There's No Model Answer│A Tricky Solution That Shows Your Sense
Chapter 15: The Art of Imagination
Imagining a wider scope│Hypothesis and verification
Chapter 16: The Art of Transition
Thinking Flexibly│Turning and Flipping to See from a Different Perspective
Chapter 17: The Art of Finding
Euclidean Geometry: Just Know This│There's no problem you can't solve if you just find the special shapes.
Chapter 18: The Art of Manipulation
Actively Intervene in the Problem│Examine the Conditions of the Problem
Chapter 19 Step Skills
From whole to part│Finding common parts
Chapter 20: The Art of Understanding
Converting given information into necessary information│An easy and simple way to approach problems│Finding length and area from an angle

Epilogue: Euclidean Geometry is Fun

Why were great advances made in ancient Greece with limited knowledge?
Euclidean geometry, ancient Greek mathematics that breaks the mold of correct answers and discovers various possibilities

How can I excel in math? Most students study math by skipping the material and memorizing model answers.
However, students who study like that not only fail to develop interest in mathematics, but also are unable to solve problems that deviate slightly from the pattern.
This is the result of forgetting that thinking and understanding take precedence over calculation and memorization.
"Euclidean Geometry: The Art of Problem Solving" is a book that helps develop mathematical thinking and problem-solving skills that were lost through Euclidean geometry, a mathematics from around 300 BC.
In ancient Greece, mathematics was needed for practical purposes such as building houses and measuring land, so most of the mathematics was geometry, which involved drawing lines and shapes to find angles and lengths.
The core of this book is that it can awaken us to the essence of mathematics through the thinking of the ancient Greeks, who created a great civilization with limited knowledge.
As you solve Euclidean geometry problems, you will find clues that can help you solve everyday problems.
Author Jong-ha Park, a KAIST graduate, PhD in mathematics, and creativity consultant, continues his best-selling book in the field of mathematics, "Mathematics: The Art of Thinking UP," proving once again that "mathematics is not memorization, but thinking."


No knowledge required! There's no problem you can't solve because you don't know the concept.
Learn basic geometric knowledge and thinking skills through 153 problems that capture only the essence of ideas.

Euclidean geometry begins with the simple premise that 'alternating angles are equal.'
Euclidean geometry is the process of applying this proposition to various situations to solve problems.
The greatest characteristic of Euclidean geometry problems is that they can be solved with minimal knowledge, and the problems introduced in this book can also be enjoyed with only a fourth-grade elementary school level of mathematical knowledge.
The author selected 153 of the most effective problems from over 1,000 Euclidean geometry problems and included them in this book.
It is no exaggeration to say that if you can solve these problems well, you can solve the geometry problems on the CSAT without even touching them.
Don't worry if you don't have a 4th grade level of math knowledge.
Part 1 explains in simple yet detailed terms the minimum knowledge required to solve the problem.
It contains all the basic properties of shapes that you need to know, from Euclid's axioms to the characteristics of triangles, squares, and circles.
In Part 2, we explore Euclidean thinking in earnest.
It teaches thinking skills that can be applied to all problems, including mathematics, such as dividing something unfamiliar into something familiar and understanding their relationships.

Euclidean geometry, the art of problem-solving that solves even the complex problems of everyday life.
Connect the dots, connect the lines, paste, cut and flip the shapes like Euclid!

In Part 3, problem-solving techniques are presented in seven categories based on the basic Euclidean geometry knowledge and Euclidean thinking method discussed in Parts 1 and 2.
Let's get the secret weapon that can help you not only get good grades but also solve everyday problems.

·The art of cheating: One way to study math is to memorize model answers.
But model answers aren't the only correct answers.
The more you solve problems in different ways, the more your math skills will improve.
Especially, if you solve many tricks that seem like shortcuts, your mathematical sense will increase.

·The art of imagination: The charm of Euclidean geometry is revealed when you imagine what is not presented in the problem.
Since most problems only give you a part of the overall situation, you can often get an idea for solving the problem by simply drawing an extension or auxiliary line and expanding the situation slightly.
·The art of transition: When you look at it from a different perspective, you can see the clues to a problem that was previously unsolvable.
In fact, you can find the answer by turning your head, turning the problem sideways, or sometimes even turning it upside down.

·The art of finding: Problems are often solved by finding shapes that are familiar to us.
For Euclidean geometry problems, the right triangles (30°, 60°, 90°) and (45°, 45°, 90°) are the key.
·The art of manipulation: Problems are solved by actively intervening in them rather than passively waiting for ideas to come to you.
In particular, it requires the manipulation of cutting out a specific part and pasting it in an appropriate location.
By handling and manipulating paper with my own hands, I can also develop an eye for problem-solving.
·Step-by-step technique: After considering the overall situation, you must solve the problem by determining the order of each step.
What is needed is a strategy that approaches the problem in a macroscopic way.
Don't be afraid. Break the problem down into pieces and you will find that even problems that were previously unsolvable will be solved.

·The art of comprehension: You must gather all the information necessary to solve the problem.
The more information you have, the easier and faster you can solve problems.
The first thing you need to do manually is to mark the problem with the necessary information.
Let's not forget that math problems are solved with our hands, not our eyes.