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Math
A |
Perimeter
and Circumference |
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Perimeter
is the word used to describe the distance around the outside
of a figure.
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To find
the perimeter,
add together the lengths of all of the sides of the figure. |
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Circumference
is the word used to describe the distance around the outside of a
circle.
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Use
when you know the radius. |
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Use
when you know the diameter. |
Example 1:
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Ed and Carol
are jogging around a circular track in the park. The
diameter of the track is 0.8 miles. Find to the nearest
mile, the number of miles they jogged if they made two complete
trips around the track. |
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= (3.141592654)(0.8) = 2.513274123 miles (one
trip)
2(2.513274123) = 5.026548246 = 5 miles
This problem is shown being done
with full calculator (TI-83+) entries.
Work should be held in the calculator until the final rounding of the
answer occurs.
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Example 2:
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For an art
project at school, you need a piece of string long enough to wrap
around the outer edge of this starfish. What is the shortest
possible length for the string? |
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Perimeter = 2 +
1.5 + 1 + 2 + 1.5 + 2 + 2 + 3 + 2.5 + 2
= 19.5 inches |
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