Shortest Distance between a Point and a Line in 2D

This Demonstration shows how the scalar product (dot product) can be used to find the point of shortest distance between a point P and a line. You can modify the line by dragging points A and B.

This Demonstration is intended for teachers trying to illustrate how the inner product (dot product) - )· becomes zero when the point X on the line AB is closest to the point P. The Demonstration can be used as an interactive board; teachers can keep their students' attention on a given element by not displaying other elements.