The document discusses the Pythagorean theorem and distance formula. The Pythagorean theorem states that for any right triangle, a2 + b2 = c2, where c is the hypotenuse and a and b are the legs. The distance formula calculates the distance between two points in a plane by taking the difference of their x- and y-coordinates and plugging them into the formula (x2 - x1)2 + (y2 - y1)2. An example of using each formula to solve for the length of a side of a triangle and the distance between two points is provided.