Finsler-Hadwiger Theorem
Let the Squares 
and 
share a common Vertex 
. The midpoints 
and 
of the segments 
and 
together with the centers of the original squares 
and 
thenform another square 
. This theorem is a special case of the Fundamental Theorem of Directly SimilarFigures (Detemple and Harold 1996).
References
Detemple, D. and Harold, S. ``A Round-Up of Square Problems.'' Math. Mag. 69, 15-27, 1996. Finsler, P. and Hadwiger, H. ``Einige Relationen im Dreieck.'' Comment. Helv. 10, 316-326, 1937. Fisher, J. C.; Ruoff, D.; and Shileto, J. ``Polygons and Polynomials.'' In The Geometric Vein: The Coxeter Festschrift. New York: Springer-Verlag, 321-333, 1981.
- Schröder-Bernstein Theorem
- Schröder Number
- Schröder's Equation
- Schröder's Method
- Schröter's Formula
- Schur Algebra
- Schur Functor
- Schur Matrix
- Schur Multiplier
- Schur Number
- Schur's Inequalities
- Schur's Lemma
- Schur's Problem
- Schur's Representation Lemma
- Schur's Theorem
- Schwarzian Derivative
- Schwarz-Pick Lemma
- Schwarz Reflection Principle
- Schwarz's Inequality
- Schwarz's Triangle Problem
- Schwarz Triangle
- Schwenk's Formula
- Schönflies Symbol
- Schönflies Theorem
- Scientific Notation