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 calculates the distance between two points and involves taking the difference of the x-coordinates squared and the difference of the y-coordinates squared and adding those values together. Examples of using both the Pythagorean theorem and distance formula are provided.