Use the concept of an average to establish the formula for the midpoint, M, of the interval joining two points (x1,y1) and (x2,y2) on the Cartesian plane: M(x,y) = (x1 + x2 / 2, y1 + y2 / 2)

1. Middle of the Line - Find midpoint co-ordinates
2. Middle of the Line - Find midpoint co-ordinates