# Terry's Maths Collections

- Author:
- Terry Tam

## Table of Contents

### It's all about triangles...

- How to reconstruct a quadrilateral farm to a triangular one with the same area?
- Why are the areas of both triangles the same?
- Why is ratio difference the same?
- Why do 3 trapeziums have the same area?
- Why are the areas the same?
- Which is the 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
- Why are 6 points concyclic?
- Morley Equilateral Triangles
- Napoleon Equilateral Triangles

### It's all about cyclic quadrilaterals...

### Famous Puzzle Gallery

### Origami

### Proofs without words

### Elegant Solution

### Art Gallery