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10.3 Circumference of a Circle
Objective: Find the circumference of a circle.
Joseph Williams GESD jwilliams@gesd40.org
Image: 'Olive oil bubble variations'
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2. What part of the circle does he draw?
Image: 'tips'
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3. Circle ­ the set of all points in a plane that are
the same distance from a point called the
center.
Image: 'Olive oil bubble variations'
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4. Center ­ The point inside a circle that
is the same distance from all the points
on a circle.
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5. Radius ­ The
distance from the
center of a circle to
any point on the
circle.
Image: 'blood orange'
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6. Diameter ­
the distance
across the
circle
through its
center.
Image: 'blood orange'
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7. Circumference ­
the distance
around a circle
(the perimeter of a
circle).
Image: 'blood orange'
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8. pi ­ the
ratio of the
circumference
of a circle to its
diameter.
(3.14) Image: 'Pi sculpture'
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9. Diagram of a Circle
Radius
Diameter
Center
Circumference
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10. Label Each Circle
Center Radius
Diameter Circumference
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11. Multiplying Decimals
1. Line up the numbers.
2. Multiply like you would any
other number.
3. Count over for your decimal
place in your answer.
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12. Finding Circumference
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C = 2 r C = 2 3.14 5
C = 31.4
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C = d C = 3.14 12
C = 37.68
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