The document defines key terms related to circles: 1. A circle consists of all points equidistant from a fixed center point. 2. A radius is a line segment from the center to any point on the circle. All radii are equal in length. 3. A diameter passes through the center and connects any two points on the circle. The diameter is twice as long as the radius.

1. MATHEMATICS
Geometry
Circle andits
Parts

2. A circle

3. Many musical instruments have a circular surface.
For example:
Bingo Drum Tabla
Snare Drum Bass Drum

4. Five rings in the logo of Olympic games
A circle

5. 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.

6. 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.
CentreO
This fixed point (equidistant)
inside a circle is called
centre.
A circle has one and only
one centre.

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

8. K
Centre O
L
Radii ( plural of radius) of a circle are equal in length.
Infinite number of radius can be drawn in a circle.
M
N
(Contd…)

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

10. A circle
(Contd…)
P
Centre
A
Q
B
N
Infinite number of diameters can be drawn in a circle.
As the radii of a circle are equal in length, its diameters too

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

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

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

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

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

16. K
C
KC
Secant KC
O
Centre
It is a line that intersects the circle at any two point
on the circle
line that contains a chord

17. K
C
KC
Secant KC
O
Centre
X
A
D
Infinite number of secants can be drawn in a circle.

18. K
C
O
Centre
C
It is a line that intersects the circle at exactly one
point on the circle. This point is called Point of
Tangency.
Point of
Tangency

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

20. O
Centre
L
K
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.
X
Naming an arc
Arc KXL
(Contd…)

21. L
X
Minor Arc KXL
K
O
Centre
Major Arc KYL
Y
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…)

22. An arc

23. Half of a circle is called a semicircle.
O
Centre
Diameter
D E
S
A semicircle is also an arc of the circle.
R
(Contd…)
Semicircle DSE
Semicircle DRE

24. Radius Diameter Chord Arc
Semi
Centre
O
Circle

25. Radius Diameter Chord Arc
Semi
M
O Centre
Circle

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

27. Radius Diameter Chord Arc
Semi
Q
P
O
Centre
Circle

28. Radius Diameter Chord Arc
Semi
Centre
O
Circle

29. S
Diameter
Semicircle
D E
Sem
Semi
circle
Radius Diameter Chord Arc
O
Centre
Semicircle

30. M
O Centre
X
Secant Tangent

31. E
D
Diameter DE
O
Centre
T
Tangent
DT
Point of Tangency
Secant Tangent

32. 1. The distance between any
two points on the
circumference of a circle.
2. A line segment that joins
any two points on a circle.
3..The line segment that joins
any two points on the
circle and passes through
its center.
4. Line segment that joins any
point on the circle to its
centre .
5. Line that intersects the
circle at any two point on
the circle.
6. line that intersects the circle
at exactly one point on the
circle
Direction: Fill in the box
the answers of its
corresponding statements
shown on the right.
Hint: The last letter of the
answer will be the first
letter of next answer.

33. Across:
1. the distance between any
two points on the
circumference of a circle.
2. A line segment that joins
any two points on a circle.
3..The line segment that joins
any two points on the
circle and passes through
its center.
4. Line segment that joins any
point on the circle to its
centre .
5. Line that intersects the
circle at any two point on
the circle.
6. line that intersects the circle
at exactly one point on the
circle
A
Direction: Fill in the box
the answers of its
corresponding statements
shown on the right.
Hint: The last letter of the
answer will be the first
letter of next answer.