Chord length and distance for centre of the circle

For a chord the distance from the center is the perpendicular distance of the chord such that it passes through the center.

Objectives

Understand the relation between chord length and distance from the center

Estimated Time

30 minutes

Prerequisites/Instructions, prior preparations, if any

Prior knowledge of point, lines, angles, polygons

Materials/ Resources needed

• Digital : Computer, geogebra application, projector.
• Non digital : Worksheet and pencil, compass, strings
• Geogebra files : Chord length and perpendicular distance.ggb

Download this geogebra file from this link.

Process (How to do the activity)

• For a chord in a circle construct a perpendicular through the center of the circle.
• Move chord closer to center of the circle, note the perpendicular distance in the worksheet.
• What can you notice between chord length and perpendicular distance? When is the perpendicular distance equal to zero?

Observation	Chord 1 Length	Distance from centre	Chord 2 Length	Distance from centre