Math Education

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Math Education

• Educational Technology
• EDU 529
• Jun 30, 2003
• David Bloom

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Pi (p) and the Circle
Circumference
Pi (p)
Radius
r d / 2
d 2 r
Pi (p) 3.141592654 . . . . .
radius
diameter
Diameter
Center
d 2 r
Circle
C p d 2 p r
Area
Perimeter
A p r 2
C / d p
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Prior Knowledge About Rectangles

• Area Length (Base) x Width (Height)
• 3 x 1 3 square units
• Perimeter Sum Length of the Outer Sides
• 1 3 1 3
• 8

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Vocabulary

• Circle
• A circle is the set of points equidistant from a
  given point

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Vocabulary

• Circumference
• The perimeter of a circle is called the
  circumference

r
C
Circumference C
O
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Vocabulary

• Radius
• The distance from the center of the circle to its
  perimeter is called the radius

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Vocabulary

• Diameter
• The diameter is the distance from one point on a
  circle to another point on a circle which passes
  through the center

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Vocabulary

• Pi
• The number, Pi, denoted p, is defined as the
  ratio of a circles circumference C to its
  diameter d

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Formula

• Circumference
• The circumference of a circle can be calculated
  using the formula

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Formula

• Area of a Circle
• The area of a circle can be calculated using the
  formula

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Area of Circle Step by Step
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Application
Circumference We use    with formulas to find
the circumference of circles. For example, if you
are given the diameter of a circle, you can find
the circumference by using this formula
                                                  
                           Another formula for
finding the circumference of a circle is
                                                  
                                         
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Pie r not round,Pie r square (p r2)
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Acknowledgements

• Music by
• Don McLean, American Pie, 1972