The document defines and explains key terms related to circles: 1. A circle is a closed curve in which all points are equidistant from the center. It has properties like radius, diameter, circumference, chords, arcs, and segments. 2. Key terms are defined, like radius as the line from the center to the edge, diameter as a chord passing through the center, and circumference as the distance around the circle. 3. Examples are given of circles in daily life, music, and sports to illustrate the concept. Diagrams accompany the definitions of terms like chord, arc, semicircle, and segments.

1. MATHEMATICS STANDARD : VI Circle

2. Contents Circle in daily life Circle in music Circle in sports Circle Centre Circumference Circular region Radius Diameter Chord Arc Semicircle Segments of a circle Crossword S Radius OM Centre M Chord PQ P E D Q G Arc RE O F Diameter DE

3. CIRCLE IN DAILY LIFE A circle BACK

4. CIRCLE IN MUSIC BACK Many musical instruments have a circular surface. For example: Bingo Drum Tabla Snare Drum Bass Drum

5. CIRCLE IN SPORTS Five rings in the logo of Olympic games BACK A circle

6. A circle can be drawn with the help of a circular object. For example: A circle drawn with the help of a coin. A circle is a closed curve in a plane. What is a Circle? BACK

7. This fixed point (equidistant) inside a circle is called centre. Circle and Centre of a circle A circle is a closed curve consisting of all points in a plane which are at the same distance (equidistant) from a fixed point inside it. O Centre A circle A circle has one and only one centre.

8. The distance around a circle is called its circumference. O Centre Circumference A circle A

9. Circular Region A circle divides a plane into three parts. 2. Interior of a circle 3. Exterior of a circle A plane The interior of a circle together with its circumference is called the circular region. O Centre 1. The circle

10. Radius A line segment that joins any point on the circle to its centre is called a radius. M A point on the circle Radius (Contd…) Centre O

12. Diameter AB A line segment that joins any two points on the circle and passes through its centre is called a diameter . A B A circle Diameter (Contd…) O Centre

14. The length of the diameter of a circle is twice the length of its radius. Radius OM Centre M O N Radius ON Diameter MN Diameter MN = Radius OM + Radius ON Radius OM = Radius ON (Contd…)

15. Chord A line segment that joins any two points on the circle is called a chord . O B A A is a point on the circle B is another point on the circle A line segment that joins point A and B Chord

16. Diameter is also a chord of the circle. O Chord CD C D M N K L Chord MN Chord KL (Contd…) Diameter CD

17. The diameter is the longest chord . O Diameter CD C D M N Chord MN (Contd…) C D M N Chord KL L K

18. L K M N Chord MN Infinite number of chords can be drawn in a circle. Chord KL Chord GH G H BACK O Centre

19. Arc An arc is the distance between any two points on the circumference of a circle. Arc (Contd…) O Centre K L

20. An arc is named by three points , of which two are the end points of the arc and the third one lies in between them. Naming an arc (Contd…) Arc KXL O Centre L K X

21. X An arc divides the circle into two parts: the smaller arc is called the minor arc , the larger one is called the major arc . (Contd…) O Centre L K Y Minor Arc KXL Major Arc KYL

22. Example of an arc An arc An arc

24. E Diameter Semicircular region Semicircular region The diameter of a circle divides it into 2 semicircular regions. D BACK Centre O Semicircle DSE Semicircle DRE

25. Segments of a Circle A chord divides the circular region into 2 parts , each of which is called a segment of the circle. Centre O D E Chord DE Minor segment of a circle Major segment of a circle S R (Contd…)

27. Radius Diameter Chord Arc Semi Circle Centre O Recap the Terms

28. Radius Diameter Chord Arc Semi Circle Radius OM Centre M O

29. Radius Diameter Chord Arc Semi Circle Centre E D Diameter DE O

30. Radius Diameter Chord Arc Semi Circle Centre Chord PQ P Q O

31. Radius Diameter Chord Arc Semi Circle Centre E G O F Arc PQR

32. Radius Diameter Chord Arc Semi circle S Centre O Diameter Semicircle D E Semicircle Semicircle DSE

33. C 2 C U M F E R N C E A E I Down 1. The distance between any two points on the circumference of the circle. 2. The distance around the circle. 3. The distance from the centre of the circle to a point on the circle. R D I U S R 1 C 3 R A Across: 4. The line segment that joins any two points on the circle and passes through its centre. 5. A closed curve in a plane. 6. All points on the circle are equidistant from this point. 7. A line segment that joins any two points on a circle. 4 D A M T E E 5 I R L E 6 C E N T E H R O D 7 Circle Crossword

34. Created by The Department of Research Bombay Cambridge Gurukul The End