Perimeter and Area Grade 3 online exercise for - Free Printable

Problem Explanation:

The worksheet involves calculating the area and perimeter of various shapes. The first part requires finding the area and perimeter by counting squares, while the second part involves calculating the area using the formula \( \text{Area} = \text{length} \times \text{width} \).

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Solution:

#### Part 1: Find the area by counting the squares

1. Shape 1 (Blue):
- Area: The shape is a rectangle with 3 rows and 4 columns.
\[
\text{Area} = 3 \times 4 = 12 \text{ square units}
\]
- Perimeter: The perimeter is the sum of all sides.
\[
\text{Perimeter} = 2 \times (\text{length} + \text{width}) = 2 \times (4 + 3) = 2 \times 7 = 14 \text{ units}
\]

2. Shape 2 (Green):
- Area: The shape is a rectangle with 2 rows and 2 columns.
\[
\text{Area} = 2 \times 2 = 4 \text{ square units}
\]
- Perimeter:
\[
\text{Perimeter} = 2 \times (\text{length} + \text{width}) = 2 \times (2 + 2) = 2 \times 4 = 8 \text{ units}
\]

3. Shape 3 (Purple):
- Area: The shape is a rectangle with 3 rows and 5 columns.
\[
\text{Area} = 3 \times 5 = 15 \text{ square units}
\]
- Perimeter:
\[
\text{Perimeter} = 2 \times (\text{length} + \text{width}) = 2 \times (5 + 3) = 2 \times 8 = 16 \text{ units}
\]

4. Shape 4 (Pink):
- Area: The shape consists of 6 individual squares.
\[
\text{Area} = 6 \text{ square units}
\]
- Perimeter: Count the outer edges. There are 14 edges.
\[
\text{Perimeter} = 14 \text{ units}
\]

5. Shape 5 (Light Blue):
- Area: The shape consists of 5 individual squares.
\[
\text{Area} = 5 \text{ square units}
\]
- Perimeter: Count the outer edges. There are 12 edges.
\[
\text{Perimeter} = 12 \text{ units}
\]

6. Shape 6 (Yellow):
- Area: The shape consists of 10 individual squares.
\[
\text{Area} = 10 \text{ square units}
\]
- Perimeter: Count the outer edges. There are 18 edges.
\[
\text{Perimeter} = 18 \text{ units}
\]

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#### Part 2: Find the area by multiplying the length × width

7. Shape 7 (Blue Rectangle):
- Dimensions: Length = 9 mm, Width = 5 mm
- Area:
\[
\text{Area} = \text{length} \times \text{width} = 9 \times 5 = 45 \text{ mm}^2
\]

8. Shape 8 (Yellow Rectangle):
- Dimensions: Length = 8 cm, Width = 2 cm
- Area:
\[
\text{Area} = \text{length} \times \text{width} = 8 \times 2 = 16 \text{ cm}^2
\]

9. Shape 9 (Red Square):
- Dimensions: Side = 7 m
- Area:
\[
\text{Area} = \text{side} \times \text{side} = 7 \times 7 = 49 \text{ m}^2
\]

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Final Answers:

\[
\boxed{
\begin{array}{ll}
\text{1. Area: } 12, \text{ Perimeter: } 14 \\
\text{2. Area: } 4, \text{ Perimeter: } 8 \\
\text{3. Area: } 15, \text{ Perimeter: } 16 \\
\text{4. Area: } 6, \text{ Perimeter: } 14 \\
\text{5. Area: } 5, \text{ Perimeter: } 12 \\
\text{6. Area: } 10, \text{ Perimeter: } 18 \\
\text{7. Area: } 45 \text{ mm}^2 \\
\text{8. Area: } 16 \text{ cm}^2 \\
\text{9. Area: } 49 \text{ m}^2 \\
\end{array}
}
\]