Coordinate Geometry – Notes

Distance Formula

The distance between the points (x₁y₁) and (x₂,y₂) is given by :

The distance of the point (x, y) from origin is given by :

Three points A, B and C are collinear if AB + BC = AC

Section Formula

The section formula states that any point P(x, y) that divides a line segment in the ratio m:n can be represented as  ( )

The following are the corollaries f the section formula :

• The midpoint of a line segment joining (x₁, y₁) and (x₂, y₂) is: ( , )
• The centroid G of a triangle, with vertices ( ), ( and (  is:                        ( , )