# Parabola as Locus of Points

Move point

*C*and observe what happens.The green trace generated by point

*D*is a parabola. A

*parabola*is the set of points equidistant from a given point (

*focus*) and from a given point (

*directrix*). In the applet above, point

*B*is the locus and the red line is the directrix.