Combinatorial techniques can frequently provide satisfying “explanations” of various mathematical phenomena. In this thesis, we seek to explain a number of well known number theoretic congruences using combinatorial methods. Many of the results we prove involve the Fibonacci sequence and its generalizations.

In this thesis, we provide constructive proofs of serveral generalizations of Sperner's Lemma, a combinatorial result which is equivalent to the Brouwer Fixed Point Theorem. This lemma makes a statement about the number of a certain type of simplices in the triangulation of a simplex with a special labeling. We prove generalizations for polytopes with simplicial facets, for arbitrary 3-polytopes, and for polygons. We introduce a labeled graph which we call a nerve graph to prove these results. We also suggest a possible non-constructive proof for a polytopal generalization.