CIRCLE

By Vinay

Specific ObjectivesKnowledge : Student will able to recall the circle and its

parts.

Understanding :Student will able to explain the parts of

circle like diameter , chord , segment , etc.

Skill :Student will able to draw the circle and its parts.

Application : Student will able to analyse things which are

in circle shape.

Teaching points1. Circle

2. Parts of Circle Radius Diameter Chord Concentric circles

Arc Segment Semicircle Secant and

Tangent

CIRCLE

Definition : A circle is set of points in plane that are equidistant from a given fixed point in plane.Thus , a circle is path traced by point in a plane which moves such that its distant from fixed point in plane is a constant. The fixed point is called centre.

Centre

A circle

Examples

PARTS OF CIRCLE

1. RadiusDefinition : A radius of a circle

is a line segment joining the

centre to any point on the circle .

Infinite number of

radius can be drawn in a circle .

Radii of circle are equal in

length.

2. Diameter

Definition : A diameter of a circle is line segment that joints any

points on the circle and passes through its centre.

Infinite number of diameters can be drawn in a circle an

are equal in length.

3.ChordDefinition : A line segment that joins any two points on the

circle is called chord .

Diameter is also longest chord of the circle . Infinite number

of chords can be drawn.

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4.ArcDefinition : An arc of a circle is a

part of circle included between

two distinct points of the circle.

Any chord other than the

diameter divides the

circumference into two unequal

parts , two unequal arcs.

The larger arc is called major arc

and the smaller one is called

minor arc.

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The longest arc of circle which forms the circle is called circumference

5 Segments of a circleDefinition : A chord divides the

circular region into two parts,

each of which is called a

segment of circle.

The segment that contains

centre inside is called major

segment . The segment doesnot

contain the centre is called

minor segment.

6. Semicircle

Definition : The diameter of a circle divides it into

two equal halves and each half is called semicircle.

7. Secant &TangentDefinition : A line that intersects a circle in two distinct points is called a secant.Definition : A line that just touches circle atone point at outside is called tangent.

Definition : Two or more circles in same plane are called

concentric circles if they have same centre.

Concentric Circles

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Video

EvaluationFill in the blanks with suitable answers.

1. The fixed point is called

2. Line joining centre to any point on the circle is called

3. is the longest chord of circle.

4. The larger arc is called

5. The longest arc of circle which forms the circle is called

Answers

1. Centre.

2. Radius.

3. Diameter.

4. Major arc.

5. Circumference.

Thank you