The document explains the Pythagorean theorem and distance formula. The Pythagorean theorem states that the sum of the squares of the two sides of a right triangle equals the square of the hypotenuse. The distance formula calculates the distance between two points by taking the difference of their x- and y-coordinates and plugging them into the formula (x2-x1)2+(y2-y1)2. Examples are provided to demonstrate the application of each formula.