The document discusses the Pythagorean theorem and distance formula. The Pythagorean theorem states that for any right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. The distance formula uses the Pythagorean theorem to calculate the distance between two points in a coordinate plane by treating it as the hypotenuse of a right triangle formed by the two points. The document provides an example of using the distance formula to calculate the distance between points (7,5) and (5,3).