Circles

                                                                        CIRCLES...

INTRODUCTION:

            You may have come across many objects in daily life, which are round in shape, such aswheels of vehicle, bangles, buttons of shirt, coins, key rings etc. In a clock, you might have observed that the second's hand goes round the dial of the clock rapidly and its tip moves in a round path.This path traced by the tip of the second's hand is called circle. In this chapter we will study about the circles and other related terms to it.

CIRCLES AND ITS RELATED TERMS:

1)LOCUS: It is defined as a path traced by the point such that each and every point of the path follows the same rule.

2)CIRCLE: It is defined as the locus of a point which moves in such a way that its distance always remains constant from some fixed point which is known as center of the circle and the constant difference is called radius of the circle.     

3)SEMI CIRCLE: An arc of a circle whose end points are the end points of the diameter is called a semi-circle. The degree measure of a semi circle is 180.

4)ARC:The continuous part of a circle is called an arc.

5)Minor Arc:An arc of a circle having length less than the semi circle is called minor arc . The degree measure of minor arc is less than 180.

6)Major Arc:An arc of a circle having length greater than the semi circle is called major arc. The degree measure of major arc is greater than 180 but less than 360.

7)Segment:The area of a circle bounded by a cord and corresponding arc is called segment of the circle.

8)Minor Segment:The area of circle bounded by the cord and minor arc is called minor segment.

9)Major Segment:The area of circle bounded by the cord and major arc is known as major segment.

10)Sector:The area of circle bounded by two radii and the corresponding arc is called sector of the circle.

11)Minor Sector:The area bounded by two radii and the corresponding minor arc is known as minor sector.

12)Major Sector: the area bounded by two radii and the corresponding major arc is known as major sector.

13)Secant Of a Circle:A line which intersects a circle into two points having either one end or both the ends outside the circle is called secant of a circle.

NOTE:A circle divides the plane on which it is drawn in three parts i.e interior, exterior and circumference.