Section 6-1

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Take out a ruler and your calculator.
stamped.
Find the missing angle measure and any
missing side lengths.
Pi
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Calculate pi, the ratio of the circumference of
a circle to its diameter.
Use the ratio pi to find missing distances.
Use problem solving skills.
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The distance around a
polygon is called the
perimeter
Perimeter
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The distance around a
circle is called the
circumference
Circumference
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Height of a tennis
ball can?
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Circumference of
the canister?
Let’s try it !!!
The circumference of the canister is greater than the height of the
canister or three tennis balls.
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In this investigation you will find an
approximate value for π by measuring
circular objects and calculating the ratio of
the circumference to the diameter. Lets see
how close you come to the actual value of π.
Object
Circumference
Diameter
Ratio C/d
Practice
The distance from the center of a Ferris wheel
to one of the seats is approximately 90 ft, what
is the distance traveled by a seated person, to
the nearest foot, in one revolution?
Partner challenge
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Calculate pi, the ratio of the circumference of
a circle to its diameter.
Use the ratio pi to find missing distances.
Use problem solving skills.
1.
2.
If a circle has diameter of 13cm, what is its
circumference?
If a circle has a circumference of 25cm,