Arc of a circle

The part of the circumference within the two points in either directions are called its arcs.

Objectives

 * The students learn that an arc is a part of a circle included between two distinct points on the circumference of the circle.
 * The students learn that the the larger arc is called major arc and the smaller one is called minor arc.

Estimated Time
10 minutes

Prerequisites/Instructions, prior preparations, if any

 * The students should know to draw a circle using compass.
 * They should know that arc is part of the circumference.

Materials/ Resources needed

 * Digital : Computer, geogebra	application, projector.
 * Non	digital : Worksheet	and pencil, compass, strings
 * Geogebra	files : Arcs	in a circle	.ggb

Process (How to do the activity)

 * If	the circle is divided into 2 parts?
 * How	many arcs are formed?
 * Are	the two arcs equal?
 * Establish	minor arc(smaller arc) and major arc(larger arc)
 * Compare	region enclosed by major arc and minor arc, which is larger?
 * Establish	sector – major sector and minor sector
 * Animate	the geogebra file to show a major arc becomes a minor arc.
 * If	one is major arc, the other is a minor arc; can the two arcs be	equal?What are they called?
 * How	are the two points	with respect to center of the circle when arcs are equal.
 * If	the angle between the radii is fixed but radius of the circle is	increased, what can you say about the two arcs?
 * Evaluation
 * 1) What is the longest arc of a circle called?
 * 2) What are the arcs called when both major and minor arcs are of same size?