Let's solve each problem step by step.
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🔷 Perimeter of a Rectangle Formula:
$$
\text{Perimeter} = 2 \times (\text{length} + \text{width})
$$
We'll apply this formula to each rectangle.
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1) Rectangle: 3.2 cm × 2.8 cm
$$
P = 2 \times (3.2 + 2.8) = 2 \times 6.0 = 12.0 \text{ cm}
$$
✔ Perimeter = 12.0 cm
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2) Rectangle: 1¼ in × ¾ in
Convert mixed numbers to decimals:
- $1\frac{1}{4} = 1.25$ in
- $\frac{3}{4} = 0.75$ in
$$
P = 2 \times (1.25 + 0.75) = 2 \times 2.0 = 4.0 \text{ in}
$$
✔ Perimeter = 4.0 in
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3) Rectangle: 5.3 cm × 2.5 cm
$$
P = 2 \times (5.3 + 2.5) = 2 \times 7.8 = 15.6 \text{ cm}
$$
✔ Perimeter = 15.6 cm
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4) Rectangle: 1¼ m × 2½ m
Convert to decimals:
- $1\frac{1}{4} = 1.25$ m
- $2\frac{1}{2} = 2.5$ m
$$
P = 2 \times (1.25 + 2.5) = 2 \times 3.75 = 7.5 \text{ m}
$$
✔ Perimeter = 7.5 m
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5) Rectangle: 4¼ ft × 1½ ft
Convert to decimals:
- $4\frac{1}{4} = 4.25$ ft
- $1\frac{1}{2} = 1.5$ ft
$$
P = 2 \times (4.25 + 1.5) = 2 \times 5.75 = 11.5 \text{ ft}
$$
✔ Perimeter = 11.5 ft
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6) Rectangle: 6.7 m × 3.5 m
$$
P = 2 \times (6.7 + 3.5) = 2 \times 10.2 = 20.4 \text{ m}
$$
✔ Perimeter = 20.4 m
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✔ Final Answers:
1)
12.0 cm
2)
4.0 in
3)
15.6 cm
4)
7.5 m
5)
11.5 ft
6)
20.4 m
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Let me know if you'd like these answers written in fractions instead of decimals!
Parent Tip: Review the logic above to help your child master the concept of perimeter of rectangles worksheet.
