Daniel S. Weinberg

Pythagorean Theorem, Right Triangle

Frozen waterfall.

On the East side of Adler is the Lake Michigan

Frozen overflow water surrounding trees from the adjacent lake @ Erickson Woods in Northfield, Illinois on January 1, 2009

30-60-90 Triangle with sine cosine and tangent.

An intro to Pascal's Triangle

Introduction to the integers

A 50 second intro to the world of Fibonacci numbers.