Transcript Finding Perimeter and Circumference

Perimeter &
Circumference
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Perimeter
Definition: The distance around a two-dimensional figure.
l
w
w
l
Note: (l) represents the Length, or longer side of
the rectangle. (w) represents the Width, or shorter
side of the rectangle. If no units are given, use "u".
Perimeter (P) of a rectangle is found by solving the following
formula:
P = 2l + 2w
Perimeter (P) of a square is found by doing four (4) times
S
Side (s):
P = 4s
Perimeter of a polygon is the sum of the lengths of the
sides.
56 What is the Perimeter (P) of the following
rectangle?
15 ft.
6 ft.
57 What is the Perimeter (P) of the square below?
7
58 What is the Perimeter (P) of the figure?
8 in
59 What is the Perimeter (P) of the figure?
8 cm
10 cm
3 cm
12 cm
Circumference
Definition: The outer boundary of a circle; the
"perimeter" of the circle.
Circumference
Diameter
The circumference (C) of a circle is found by using one of
the following formulas:
C = d
or
C = 2r
or
C = 2r
C = d
or
C = 2r
Diameter (d): Any straight line segment that passes
through the center point of the circle, whose endpoints
are on the circle.
Radius (r): Any line segment from the center point of
the circle, to any point on the circle---radius is 1/2 of the
Diameter. oi of the circle, to any point on the circle---radius
is 1/2 of the Diameter.
C = d
or
C = 2r
Pi (  ), a mathematical constant, is the ratio
of a circle's circumference to its diameter.
Note:
60
What is the Circumference (C) of a circle
with a radius (r) of 7cm? (Use 3.14 for π)
7 cm
61 What is the Circumference (C) of a circle with
a Diameter (D) of 11in.? (Use 3.14 for π)
11 in.
62 Find the circumference of a circle whose
radius is 2.5 meters. (Use 3.14 for π)
63 A circle has diameter 8 yds. What is its
circumference? (Use 3.14 for π)
64 The circumference of a circle is 37.68
cm. What is its radius? (Use 3.14 for π)