© 2007 M. Tallman. Perimeter (P)- the distance around a closed figure

© 2007 M. Tallman

© 2007 M. Tallman

Perimeter (P)- the distance around a closed figure.

© 2007 M. Tallman

P=16 cm?4 4 cm× =16 cm

4 cm

4 cm

4 cm

4 cm

© 2007 M. TallmanP=23 cm?

4 cm

7 cm

4 cm

7 cm

4 cm7 cm +4 cm+ = 23 cm7 cm +

© 2007 M. TallmanP=24 cm?8 3 cm× =24 cm

3 cm

3 cm 3 cm

3 cm 3 cm

3 cm 3 cm

3 cm

© 2007 M. TallmanP=24 cm?

6 cm

10 cm8 cm

6 cm 10 cm+ = 24 cm8 cm +

© 2007 M. TallmanP=24 cm?

6 cm

5 cm

4 cm4 cm

5 cm

6 cm4 cm +4 cm+ = 24 cm5 cm +5 cm +

© 2007 M. TallmanP=22 cm?

8 cm

5 cm

4 cm

5 cm

8 cm5 cm +4 cm+ = 22 cm5 cm +

6 cm3 cm

3 cm

3 cm

4 cm 3 cm

2 cm 7 cm

5 cm

?

?

?

?

?

?

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P=10 cm?

3 cm

3 cm

3 cm

P =12 cm? P =18 cm?

3 cm

6 cm

P =16 cm?

2 cm 2 cm

2 cm 2 cm

2 cm 2 cm

2 cm

P =24 cm?

7 cm

5 cm

Length (ℓ)- a side (usually the bottom) of a polygon. Width (w)- the measurement of a

perpendicular line drawn from the length to the top of the polygon.

Perpendicular Lines

ℓ ℓ

ℓ ℓ

w w

ww

© 2007 M. Tallman

© 2007 M. Tallman

Since the length (ℓ) of a square is congruent with all other sides, if you know the length of just one side, you can find the perimeter (P) for the entire square.

You can add the length 4 times.

P = ℓ+ ℓ + ℓ + ℓ

Or you can multiply the length of the base by 4.

P = 4 ℓ

1 cm

3 cm

4 cm

P = 4 × 1 cm

P = 4 × 3 cm

P = 4 ×4 cm

P = 4 cm

P = 12 cm

P = 16 cm

© 2007 M. Tallman

© 2007 M. Tallman

Since rectangles have two congruent sides, if you know the length (ℓ) and the width (w) you can find the perimeter (P) for the entire rectangle.

You can add to find the perimeter…

P = ℓ + w + ℓ + w

…or you can multiply and add.

P = 2 × (ℓ + w)

1 cm

3 cm

6 cm

4 cm

5 cm

4 cm

P 2 ×= (4 cm + 1 cm)

P = 10 cm

P 2 ×= (5 cm + 3 cm)

P = 16 cm

P 2 = ×(6 cm + 4 cm)

P = 20 cm

P = 2 × 5 cm

P = 2 ×8 cm

P 2 × 10 cm=

© 2007 M. Tallman

P

Use the formula P = ℓ + ℓ + w + w or P = 2 × (ℓ + w) to find the perimeter of the rectangle.

4 ft

12 ft

=

P =32 ft

12 ft 4 ft× (2 )+

P = 16 ft×2

© 2007 M. Tallman

P=

P = 40cm

9 cm 11 cm× (2 )+

P = 20 cm×2

11 cm

9 cm

Use the formula P = ℓ + ℓ + w + w or P = 2 × (ℓ + w) to find the perimeter of the rectangle.

© 2007 M. Tallman

P =

P = 28 yd

7 yd×4

7 yd

7 yd

Use the formula P = ℓ + ℓ + w + w or P = 2 × (ℓ + w) to find the perimeter of the rectangle.

© 2007 M. Tallman

P =

P = 14 in

3 in 4 in× (2 )+

P = 7 in×2

4 in

3 in

Use the formula P = ℓ + ℓ + w + w or P = 2 × (ℓ + w) to find the perimeter of the rectangle.

© 2007 M. Tallman

P =

P = 16 m

7 m 1 m× (2 )+

P = 8 m×2

1 m

7 m

Use the formula P = ℓ + ℓ + w + w or P = 2 × (ℓ + w) to find the perimeter of the rectangle.