3rd Grade Perimeter and Area Worksheet | Educational Resource - Free Printable

Let’s solve each problem step by step.

We are given two formulas:
- Area (A) = length × width → A = l × w
- Perimeter (P) = add all sides together → P = side + side + side + side

Since these are rectangles, opposite sides are equal. So we can also use:
→ Perimeter = 2 × (length + width)

But since the instructions say “add all sides together,” we’ll do that to be safe and clear.

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Problem 1:
Rectangle with sides 8 in and 11 in.

Perimeter:
Add all four sides: 8 + 11 + 8 + 11
= (8 + 8) + (11 + 11)
= 16 + 22 = 38 inches

Area:
Multiply length × width: 8 × 11 = 88 square inches

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Problem 2:
Rectangle with sides 10 in and 7 in.

Perimeter:
10 + 7 + 10 + 7
= (10 + 10) + (7 + 7)
= 20 + 14 = 34 inches

Area:
10 × 7 = 70 square inches

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Problem 3:
Rectangle with sides 8 in and 10 in.

Perimeter:
8 + 10 + 8 + 10
= (8 + 8) + (10 + 10)
= 16 + 20 = 36 inches

Area:
8 × 10 = 80 square inches

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Problem 4:
Rectangle with sides 6 in and 9 in.

Perimeter:
6 + 9 + 6 + 9
= (6 + 6) + (9 + 9)
= 12 + 18 = 30 inches

Area:
6 × 9 = 54 square inches

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Problem 5:
Rectangle with sides 9 in and 7 in.

Perimeter:
9 + 7 + 9 + 7
= (9 + 9) + (7 + 7)
= 18 + 14 = 32 inches

Area:
9 × 7 = 63 square inches

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Problem 6:
This is a square! All sides are 10 in.

Perimeter:
10 + 10 + 10 + 10 = 40 inches

Area:
10 × 10 = 100 square inches

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Final Answer:

1. Perimeter: 38 in, Area: 88 in²
2. Perimeter: 34 in, Area: 70 in²
3. Perimeter: 36 in, Area: 80 in²
4. Perimeter: 30 in, Area: 54 in²
5. Perimeter: 32 in, Area: 63 in²
6. Perimeter: 40 in, Area: 100 in²