Perimeter

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Perimeter
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Perimeter - the distance around a figure
You can find the perimeter of any polygon by
adding the lengths of all its sides.
4 cm
4 cm
6 cm
4 cm 4 cm 6 cm 14 cm
Perimeter 14 cm
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Find the perimeter.
1 cm
10 cm
4 cm
3 cm
4 cm
10 cm
1 cm
3 cm 10 cm 1 cm 4 cm 4 cm 1 cm 10 cm
33 cm
Perimeter 33 cm
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You can find the perimeter of a regular polygon
by multiplying the length of one side by the
number of sides.
6 cm
7 cm
7 cm x 6 42 cm
6 cm x 5 30 cm
Perimeter 30 cm
Perimeter 42 cm
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Remember a regular polygon has equal sides and
equal angles
8 cm
12 mm
8 cm x 4 32 cm
12 mm x 3 36 mm
Perimeter 32 mm
Perimeter 36 mm
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The perimeter (P) of a rectangle equals 2 times
the sum of the length (l) and the width (w).
10 cm
P 2 x (l w)
5 cm
P 2 x (10 5)
P 2 x 15
l 10 cm w 5 cm
P 30 cm
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Area
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Area - measure of the surface of a region in
square units.
Examples of Units Square Units
mm mm x mm mm2
cm cm x cm cm2
m m x m m2
in in x in in2
ft ft x ft ft2
yd yd x yd yd2
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You can use this formula to find the area of a
rectangle.
Area length x width
A l x w
5 cm width (w)
A 10 cm x 5 cm
10 cm length (l)
A 50 cm2
The area is 50 cm2.
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There is a special formula for the area of a
square.
(s side)
A s x s s2
5 cm
A s2
5 cm
A 5 cm x 5 cm 52 cm2
A 25 cm2
The area is 25 cm2.
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You can use the base and height to find the area
of a right triangle.
Math Tip The height is always perpendicular to
the base.
A 1/2 x (b x h)
A 1/2 x (6 x 4)
A 1/2 x (24)
A 12 in2
The area is 12 in2.
Remember solve inside the parenthesis first
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You can use the formula A 1/2 x (b x h) to find
the area of any triangle.
Math Tip The height is always perpendicular to
the base.
A 1/2 x (b x h)
height (h) 10 cm
A 1/2 x (4 x 10)
A 1/2 x (40)
A 20 cm2
The area is 20 cm2.
base (b) 4 cm
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You can use a formula to find the area of any
parallelogram.
D
A
12 ft
12 ft
A
D
height (h) 5 ft
5 ft
B
B
C
base (b) 12 ft
M
P
C
You can use this formula to find the area of a
parallelogram
ABP to
DCM
Slide
Area of rectangle APMD
A b x h
A 12 ft x 5 ft
A 12 ft x 5 ft
A 60 ft2
A 60 ft2