Circumference

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Circumference Area of a Circle

• MA.6.4.1 Estimate the circumference and area of
  a circle
• Period 4

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Definition

• Circumference is the distance around a circle or
  the perimeter.
• Formula Pi x diameter
• Area is the measure of the amount of surface
  enclosed by the boundary of a figure.
• Formula r x r x pi

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Example Circumference

• Formula Diameter x Pi
• Diameter 2 in.
• Pi 3.14
• 2 x 3.14 6.28 in.

2 in.
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Example Area

• Formula radius x radius x Pi
• Radius 5 cm.
• Pi 3.14
• 5 x 5 x 3.14 78.5 sq. cm.

5 cm.
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Problem
Kristle wanted to find the area and the
circumference of a circle with a diameter of 26
in. Find the area and circumference of her circle.
26 in.
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Solution

• The area of Kristles circle is 530.66 in.
  because if the diameter is 26 in. then the radius
  must be 13 in. (26/213) 13 x 13
  169 169
  x 3.14 530.66 sq. in.
• The circumference of Kristles circle is 81.64
  in. because 26 x 3.14 81.64
  

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Credits

• I give credit to my parents for giving me
  support
• I also give credit to my math teacher,
  Mr. Imamura for teaching me
  what the circumference and area is and the
  formula for each
• I also give credit to my friends (Kristle mostly)
  for helping me use
• Microsoft PowerPoint
• Definition from Connected Mathematics.
• Hope you enjoyed my fantabulous presentation on
  the circumference and the area of a circle.