Area of Rectangles | 3rd Grade PDF Measurement Worksheets - Free Printable

Let's solve each section of the worksheet step by step.

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Section A: Determine the area of the rectangles and squares

Formula for Area of a Rectangle:
$$
\text{Area} = \text{length} \times \text{width}
$$

For Squares:
Since all sides are equal,
$$
\text{Area} = \text{side} \times \text{side} = \text{side}^2
$$

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#### 1) Example (Given):
- Length = 3 ft, Width = 2 ft
- Area = $ 3 \times 2 = 6 \text{ ft}^2 $

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#### 2)
- Length = 4 ft, Width = 2 ft
- Area = $ 4 \times 2 = 8 \text{ ft}^2 $

✔ Answer: 8 ft²

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#### 3)
- Square with side = 5 ft
- Area = $ 5 \times 5 = 25 \text{ ft}^2 $

✔ Answer: 25 ft²

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#### 4)
- Length = 8 yd, Width = 3 yd
- Area = $ 8 \times 3 = 24 \text{ yd}^2 $

✔ Answer: 24 yd²

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#### 5)
- Square with side = 7 in
- Area = $ 7 \times 7 = 49 \text{ in}^2 $

✔ Answer: 49 in²

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#### 6)
- Rectangle: 9 in × 5 in
- Area = $ 9 \times 5 = 45 \text{ in}^2 $

✔ Answer: 45 in²

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✔ Section A Answers:

1. 6 ft² (example)
2. 8 ft²
3. 25 ft²
4. 24 yd²
5. 49 in²
6. 45 in²

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Section B: Check the rectangle or square with the largest area

We need to calculate the area of both shapes in each pair and choose the one with the larger area.

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#### 1)
- Left: 9 ft × 3 ft = $ 27 \text{ ft}^2 $
- Right: 7 ft × 4 ft = $ 28 \text{ ft}^2 $

→ Right has larger area

✔ Check the right rectangle

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#### 2)
- Left: Square, 4 yd × 4 yd = $ 16 \text{ yd}^2 $
- Right: 5 yd × 3 yd = $ 15 \text{ yd}^2 $

→ Left has larger area

✔ Check the left square

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#### 3)
- Left: 15 in × 4 in = $ 60 \text{ in}^2 $
- Right: 8 in × 7 in = $ 56 \text{ in}^2 $

→ Left has larger area

✔ Check the left rectangle

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#### 4)
- Left: 13 ft × 5 ft = $ 65 \text{ ft}^2 $
- Right: Square, 80 in × 80 in = $ 6400 \text{ in}^2 $

But we must compare same units!

Convert 65 ft² to in²:

- 1 ft = 12 in → 1 ft² = $ 12 \times 12 = 144 \text{ in}^2 $
- So, $ 65 \text{ ft}^2 = 65 \times 144 = 9,360 \text{ in}^2 $

Compare:
- Left: 9,360 in²
- Right: 6,400 in²

→ Left is larger

✔ Check the left rectangle

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✔ Section B Answers:

1. Right rectangle
2. Left square
3. Left rectangle
4. Left rectangle

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Section C: Find the missing measurement

Use formula:
$$
\text{Area} = \text{length} \times \text{width} \Rightarrow \text{Missing side} = \frac{\text{Area}}{\text{known side}}
$$

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#### 1)
- Area = 54 yd², One side = 6 yd
- Missing side = $ \frac{54}{6} = 9 \text{ yd} $

✔ Answer: 9 yd

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#### 2)
- Area = 84 ft², One side = 7 ft
- Missing side = $ \frac{84}{7} = 12 \text{ ft} $

✔ Answer: 12 ft

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#### 3)
- Area = 81 in², It’s a square (all sides equal)
- So, side = $ \sqrt{81} = 9 \text{ in} $

✔ Answer: 9 in

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✔ Section C Answers:

1. 9 yd
2. 12 ft
3. 9 in

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✔ Final Summary of All Answers:

#### Section A:
1. 6 ft²
2. 8 ft²
3. 25 ft²
4. 24 yd²
5. 49 in²
6. 45 in²

#### Section B:
1. ✔ Right rectangle
2. ✔ Left square
3. ✔ Left rectangle
4. ✔ Left rectangle

#### Section C:
1. 9 yd
2. 12 ft
3. 9 in

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