# Proofs

This is the new proof page. I will be highlighting mathematical proofs in the future.

**Proof Basics **

- Introduction to Mathematical Proofs
- Proof Tutorial 2: Proving the Irrationality of Square Root of 2 by Contradiction
- More examples of Proof by Contradiction
- Proof by Contradiction: Knights and Liars

**Geometry**

- Angle Sum of Polygons
- Why is the angle sum of the interior angles of a triangle equal to 180 degrees?
- A US President’s Proof of the Pythagorean Theorem
- Using Similarity to Prove the Pythagorean Theorem
- The Algebraic and Geometric Proofs of Pythagorean Theorem
- Regular Tessellations: Why only three of them?
- Platonic Solids: Why Only Five of Them?

**Trigonometry**

**Number Theory**

- Proof of the Sum of Square Numbers
- A Simple Proof of the Arithmetic Mean Geometric Mean Inequality
- Another Proof of the Sum of the First n Positive Integers
- Prime Series 3: Proof of the Infinitude of Primes
- Proof that log 2 is irrational

**Calculus**