This activity shows how we can obtain a [color=#ff7700][i]parabola [/i][color=#000000]by[/color][/color] [color=#0000ff][i]projecting[/i] [/color]a [color=#0000ff][i]circle [/i][/color]on a [color=#0000ff][i]plane [/i][/color][color=#0000ff][i]perpendicular [/i][color=#000000]to it.[/color][/color][br][br][icon]/images/ggb/toolbar/mode_move.png[/icon] Move the [color=#980000][i]vertices of the base[/i][/color] of the cube to change its size.[br][i]Move [/i]point [color=#0000ff][i]P [/i][/color]along the circle, or [i]start the animation[/i], to generate the [color=#ff7700][i]locus [/i][/color]of point [color=#ff7700][i]P'[/i][/color], which is the projection of [color=#0000ff][i]P [/i][/color]on the [i]plane perpendicular [/i]to the circle.