This lesson covers the midpoint formula. What is the midpoint formula? The midpoint formula tells us that the midpoint of a line segment that has the endpoints (x1, y1) and (x2, y2) is [(x1 + x2)/2, (y1 + y2)^2]. Students learn how to find the midpoint of a line segment with given endpoints, such as (10, 1) and (2, -7), using the midpoint formula. Students also learn how to find the endpoint of a line segment given the midpoint and the other endpoint.