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  • Terry's Maths Collections
  • It's all about triangles...
  • It's all about cyclic quadrilaterals...
  • Famous Puzzle Gallery
  • Origami
  • Proofs without words
  • Elegant Solution
  • Art Gallery

Terry's Maths Collections

Author:
Terry Tam
Terry's Maths Collections

Table of Contents

  • It's all about triangles...

    • How to reconstruct a quadrilateral farm to a triangular one with the same area?
    • Why same areas?
    • Why ratio difference is the same?
    • Why same areas? (2)
    • Why same areas? (3)
    • Shortest-perimeter Inscribed Triangle
    • Right triangle with median as a geometric mean
    • Shortest fence dividing a triangular field into halves
    • 4 Centres in a Triangle
    • Incircle and Excircles
    • Inner/Outer Triangles
    • Equilateral Triangle on 3 Concentric Circles
    • Why 6 points are concyclic?
    • Morley Equilateral Triangles
    • Napoleon Equilateral Triangles
  • It's all about cyclic quadrilaterals...

    • Intersecting Chords Theorem and Secant-Tangent Theorem
    • How to construct a bicentric quadrilateral with 3 points?
    • Equilateral triangles on a triangle
    • Simson's line
    • Where am I?
    • Why always a circle tangent?
    • Ptolemy Theorem
  • Famous Puzzle Gallery

    • Eight Queens Puzzle
    • right triangle paradox
  • Origami

    • Obtaining Fractions via Folding Paper
  • Proofs without words

    • triangular numbers-1
    • The Sum of the Cubes of the First N Natural Numbers
    • Centered Polygonal Number 中心多邊形數
    • The Pythagorean Theorem.
    • Proof without words : Area of the triangle
    • Fibonacci Numbers and the Golden Spiral - demonstration
    • Infinite Geometric Series
    • Viviani's Theorem
    • Fagnano's Problem
    • QM-AM-GM-HM Inequality
  • Elegant Solution

    • All about Pythagoras theorem...
    • What is the length of the side of equilateral triangle?
  • Art Gallery

    • Envelope and Complete Graph
    • Modular Times Table
    • Kaleidoscope
Next
How to reconstruct a quadrilateral farm to a triangular one with the same area?

New Resources

  • Pi Made of Functions
  • Ball Structure
  • Dilations Part 3: What Do You Notice?
  • Dilations Part 2: What Do You Notice?
  • Exploring Dilations

Discover Resources

  • regular polygon area g6
  • H - Fractions and attached text
  • Opposite angles
  • line segment and copy a line
  • pattern and tiles

Discover Topics

  • Median Value
  • Cylinder
  • Upper and Lower Sum or Riemann Sum
  • Root
  • Power Functions

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