Similar to 角の二等分線の定理

Napkin ring problem

Lazy caterer's sequence

Newton's theorem (quadrilateral)

Proof that e is irrational

Hardy–Littlewood inequality

Pappus's hexagon theorem

Banach–Alaoglu theorem

Banach fixed-point theorem

Tangent half-angle substitution

Pythagorean theorem

Lune of Hippocrates

Nyquist–Shannon sampling theorem

Fatou's lemma

Bézout's identity

Petr–Douglas–Neumann theorem

Helly's theorem

Poincaré–Bendixson theorem

Monge's theorem

Jacobi's formula

Dominated convergence theorem

Laplace expansion

Taylor circle

L'Hôpital's rule

Rolle's theorem

Wiles's proof of Fermat's Last Theorem

Mathematics

0.999...

Zero-dimensional space