- Proofs Without Words
- Polygonal Number 多邊形數
- Centered Polygonal Number 中心多邊形數
- Triangular Number 三角形數
- Sum of First n Odd Numbers 首n個奇數之和
- Sum of First n Squares 首n個平方數之和
- Sum of First n Cubes 首n個立方數之和
- Sum of Squares & Perfect Square 平方和與完全平方
- Difference of Two Squares 平方差 (2)
- Difference of Two Squares 平方差 (1)
- Area of Trapezium
- Proof without words: Cosine Rule (餘弦公式)
- Interior & Exterior Angles of Triangles 三角形內角和及外角
- Two Squares
- Proof of Pythagoras Theorem(1) 畢氏定理的証明(1)
- Viviani's Theorem
- Feynman's Triangle
- Area of Circles 圓面積
