A **theorem** is a statement that can be proven via logic which generally stems from a collection of postulates or axioms.^{[1]} They have been in use since Euclidean geometry as the basis of geometrical facts.^{[2]}

Some famous theorems include:^{[3]}

- The Pythagorean Theorem
- Formulas for volume and surface area
- Stokes's Theorem
- The Fundamental Theorem of Algebra
- The Inscribed Angle Theorem
- The Triangle Angle Sum Theorem