The document discusses the Pythagorean theorem and distance formula. The Pythagorean theorem is used to find the length of the unknown side of a right triangle given two other side lengths using the formula a2 + b2 = c2. The distance formula calculates the distance between any two points in a plane by taking the square root of the sum of the squared differences between their x- and y-coordinates. An example demonstrates labeling points and plugging them into the distance formula to solve for the distance.