Parabola and satelite dish (an older applet which unfortunately sometimes behaves weird with new GeoGebra)

Explore how the geometric properties of a parabola are used in satelite dishes... (further reading)

This is a Java Applet created using GeoGebra from www.geogebra.org - it looks like you don't have Java installed, please go to www.java.com

D.Kobal with GeoGebra

See some other nice examples.