Finding the Midpoint of a Line
Segment
To find the midpoint, M, of AB we can use
formula for finding point C. This works
because the M lies along AB and divides it in
a fixed ratio. So, if the midpoint of AB is point M, what must the ratio of a : b be? Since we know the ratio of a to b, we can substitute the values you wrote above back into the formula for finding a point along a line segment.