The Focus and Directrix of a Parabola

This worksheet illustrates the relationship between a parabola and its focus and directrix. Move the yellow point along the parabola.
What is the red point called?
What is the red line called?
What is the relationship between the lengths of the blue line segments?
What fact does the previous question/answer demonstrate?
Schließen
– Kristen Beck

Information: The Focus and Directrix of a Parabola