Question

worksheet 21
find the perimeter of the following rectangle-shaped figures.
1)
0.5 m
2 m
perimeter = 2 (l + b) = 2 (2 + 0.5) m
= 2 × 2.5 m = 5 m
2)
52 cm
28 cm
3)
6.5 cm
19 cm
chocolate
bar
4)
7 cm
3 cm
5)
2 m
1.5 m
a+b=
6)
27 cm
45 cm
time: minutes
teacher’s signature: .................

Explanation:

Step1: Calculate the perimeter of the second figure

The formula for the perimeter of a rectangle is \(P = 2(l + b)\). Here, \(l = 52\space cm\) and \(b=28\space cm\).

$$
LATEXBLOCK0
$$

Step2: Calculate the perimeter of the third figure

Using the formula \(P = 2(l + b)\), with \(l = 19\space cm\) and \(b = 6.5\space cm\)

$$
LATEXBLOCK1
$$

Step3: Calculate the perimeter of the fourth figure

Using the formula \(P = 2(l + b)\), where \(l = 7\space cm\) and \(b = 3\space cm\)

$$
LATEXBLOCK2
$$

Step4: Calculate the perimeter of the fifth figure

Using the formula \(P = 2(l + b)\), with \(l = 2\space m\) and \(b = 1.5\space m\)

$$
LATEXBLOCK3
$$

Step5: Calculate the perimeter of the sixth figure

Using the formula \(P = 2(l + b)\), where \(l = 45\space cm\) and \(b = 27\space cm\)

$$
LATEXBLOCK4
$$

Answer:

1. \(160\space cm\)
2. \(51\space cm\)
3. \(20\space cm\)
4. \(7\space m\)
5. \(144\space cm\)