The power point is based on the concept attainment model of teaching mathematics.It explains the parts of circle-Radius ,diameter,center,relationship between radius and diameter,chord,properties of radius,chord and diameter,types of arcs and the exterior and interior of the circle.

1. Negative
examples
Positive
examples
Triangle
Revolution
of planet
Hexagon Fan

2. Negative Positive
Square
Rotation
of planet
Kite Tyre

3. CIRCLE : Properties
, arcs and points
Std:VII

4. S P
.
O
Q
The Centre of the circle is
O.
The radius(r) of
the circle is SO.
The diameter (d)
of the circle is
PQ
PQ=2 x OP

5. Properties of
the radius &
diameter

6. Properties of radius:
A
F G
.
O
C D
B
E
H
B
AO=OB=OC=OD=OE=OF=OG=OH=-------------
All the radii of a circle are equal in length.
They are CONGRUENT to each other
A circle has innumerable
radii.

7. Properties of a
diameter:
PQ=MN=XY=ST
All the diameters of a circle are equal in
length.
All are CONGRUENT to each other
A circle has innumerable
diameters.
P
M N
Q
S
X
T
Y

8. AB=2 x OA
• (if OA=4cm
therefore AB=8cm)
AB=2 x OB
C
A B
The measure of the diameter
of any circle is twice the
length of its radius.
O

9. Chords of
a circle

10. MN is a chord
• The line segment joining any
two points on a circle is called
a chord.
PQ is the longest chord.
• The diameter is the longest chord
A circle has innumerable chords.
M
N
P
Q
O
S
.
O

11. Arcs of
a circle

12. .
O
A
B
X
A & B are 2 points on
the circle.
The 2 points divide the
circle into 2 parts.
Each part is called an
arc of the circle.
AXB is an arc.

13. The interior
& exterior
of the circle

14. .
R
.
S
.
W
.
F
.K
.
M
.
N
.
Y
.
T
.P
.Q

15. Points- K,R,S,P,M are inside the circle.
The points which are inside the circle are known as
interior points.
Points-W,T,Q,F,N,Y are outside the circle.
The points which are outside the circle are known as
exterior points.
There are innumerable points in the interior of the
circle, on the circle and in the exterior of the circle.

16. Radii
PARTS
OF THE
CIRCLE
diameters
Chords
ARCS
Exterior
POINTS
Interior
POINTS

17. Questions:

18. Q
• Name the centre of the circle.
Q
• Name the radii.
Q
• Name the diameters.
Q
• Name the chords.
• Which is the longest chord in the
circle?
A
.
O
B
C
D
E
F
G

19. Q
• Name the centre of the circle.
Q
• Which points are known as interior
points?
• Name the interior points.
Q
• Why is point F known as exterior of the
circle?
Q
• Name the arcs of the circle.
.J
.D
.
L
.I
.F
M
N
O
.K
.S
.T