1. INTERNATIONAL ISLAMIC
UNIVERSITY MALAYSIA
:: SUBJECT ::
TECHNOLOGY AND INNOVATION IN EDUCATION
:: DESIGN BY ::
GROUP 13
AHMAD ZAKI ISMAIL
MOHD ADLAN HAJI BADARUDIN
MOHD RAZIF MAZLAN
2.
3.
4. CIRCLE
APPLICATION CIRCUMFERENCE
EXERCISE
EXERCISE AREA OF
CIRCUMFERENCE
CIRCLE
OF CIRCLE
AREA OF A CIRCLE
5. CIRCLES
• Circles are part of everyday life. They
are all around us.
• Some examples of circles are
flowers, the sun, the moon, and dish
plates.
• It is important to study circles
because they are around us and
commonly use. So it is useful to know
how to figure out their circumference
6. • A circle is a shape that has all points
the same distance from its center.
Center
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7. The circumference of a circle is the
distance or perimeter around outside
the circle.
c d
c 2 r
8. • The diameter is a straight line
segment that passes through the
center of the circle.
• The radius is a line segment that joins
the center of a circle with any point
on its circumference.
Diameter (d)
Radius (r)
d 2r
# Click HERE to see from diameter and
circumference we can can prove “pi”
9. Question :
Example 1
A circle has a diameter of 7 cm. Find the
circumference
of the circle.
c d
Solution :
22
d 7, , c ?
7
c 7
22
7
22 cm
10. Question :
Example 2
A circular swimming pool has a
circumference of 88 m.
Find the diameter of the pool.
c d
Solution :
22
c 88, d ?
7
22
88 d
7
d 28 m
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11. Question :
Exercise 1
A circular flower-bed has a radius of 9
m. Find the
circumference of the flower-bed.
1
Answer : 14 m
A. 7
2
28 m
B. 7
4
56 m
C. 7
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12. You are WRONG!!!
Here is the right solution :
c d
22
r 9, d 18, , c ?
7
c 18
22
7
4
56 m
7
NEXT QUESTION
13. Question :
Exercise 2
Given the circumferences of a car wheel
is equal to 50
inches. Find the diameter of the wheel.
21
Answer :7 inches
A. 22
10
15 inches
B. 11
10
30 inches
C. 11
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14. You are WRONG!!!
Here is the right solution :
c d
22
c 50, d ?
7
22
50 d
7
10
d 15 inches
11
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17. • The amount of space inside the
boundary of a flat
(2-dimensional) object such as a
circle.
A r 2
• Here is the formula to find the area
of circle.
Cente
r
18. Example 1
Question :
A circle has a radius of 7 cm. Find the
area of the circle.
A r2
Solution :
22
r 7, , A ?
7
22 2
A 7
7
154 cm2
19. Example 2
Question :
Find the area of a circle whose
diameter is 28 m.
A r2
Solution :
22
d 28, r 14, , A ?
7
22
A 14
2
7
616 m 2
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20. Exercise 1
Question :
A circular plate has a diameter of 22
cm. Find the area
of the plate.
2
Answer :95 cm2
A. 7
2
190 cm2
B. 7
2
380 cm2
C. 7
21. You are WRONG!!!
Here is the right solution :
A r 2
22
d 22 r 11, , A ?
7
22
A 11
2
7
2
380 cm 2
7
NEXT QUESTION
22. Exercise 2
Question :
A lawn sprinkler water a circular
portion of a yard. The
radius of the circular portion is 2m.
Calculate the area of the
yard watered by the sprinkler.
4 2
6 m
Answer : 7
A. 4 2
12 m
7
B. 4 2
24 m
7
C.
23. You are WRONG!!!
Here is the right solution :
A r 2
22
r 2, , A ?
7
22 2
A 2
7
4 2
12 m
7 HOME
26. Daily life applications - wheels, gears, clocks,
rolls, and doorknob.
http://ischoolsmaabsuelojr.wordpress.com/2009/11/21/circles-in-real-life-
application/
Astronauts - telescopes equipped with
an equatorial mount to find
astronomical objects.
http://en.wikipedia.org/wiki/Setting_circles
Sports – ball in sports, sports car racing or track,
baseball running or ice-
skating, geometry of a basketball court.
http://www.physicsclassroom.com/class/circles/u6l2c.cfm
Ships and aircraft navigation – to find the shortest
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