Area of Rectangles - Mr-Mathematics.com - Free Printable

To solve the problem of determining the areas of the rectangles, we will use the formula for the area of a rectangle:

\[
\text{Area} = \text{Length} \times \text{Width}
\]

Let's go through each part step by step.

---

Part (a)

The image shows a grid with 4 rows and 5 columns. Each square in the grid represents a unit area.

- Length = 5 units
- Width = 4 units

\[
\text{Area} = 5 \times 4 = 20 \text{ square units}
\]

So, the area of rectangle (a) is:

\[
\boxed{20}
\]

---

Part (b)

The image shows a grid with 6 rows and 4 columns. Each square in the grid represents a unit area.

- Length = 6 units
- Width = 4 units

\[
\text{Area} = 6 \times 4 = 24 \text{ square units}
\]

So, the area of rectangle (b) is:

\[
\boxed{24}
\]

---

Part (c)

The image shows a grid with 3 rows and 7 columns. Each square in the grid represents a unit area.

- Length = 7 units
- Width = 3 units

\[
\text{Area} = 7 \times 3 = 21 \text{ square units}
\]

So, the area of rectangle (c) is:

\[
\boxed{21}
\]

---

Part (d)

The dimensions of the rectangle are given directly:

- Length = 4 cm
- Width = 3 cm

\[
\text{Area} = 4 \times 3 = 12 \text{ cm}^2
\]

So, the area of rectangle (d) is:

\[
\boxed{12}
\]

---

Part (e)

The dimensions of the rectangle are given directly:

- Length = 10 cm
- Width = 5.5 cm

\[
\text{Area} = 10 \times 5.5 = 55 \text{ cm}^2
\]

So, the area of rectangle (e) is:

\[
\boxed{55}
\]

---

Part (f)

The area of the rectangle is given as 30 cm², and the length is given as 6 m. We need to find the width.

First, note that the units must be consistent. Since the area is in cm², we should convert the length from meters to centimeters:

\[
6 \text{ m} = 6 \times 100 = 600 \text{ cm}
\]

Now, use the area formula to solve for the width:

\[
\text{Area} = \text{Length} \times \text{Width}
\]

\[
30 = 600 \times \text{Width}
\]

Solve for the width:

\[
\text{Width} = \frac{30}{600} = 0.05 \text{ cm}
\]

So, the width of rectangle (f) is:

\[
\boxed{0.05}
\]

---

Final Answers:

\[
\boxed{20, 24, 21, 12, 55, 0.05}
\]