7

To solve problem 7, you need to find the area of each rectangle.

1. \(3 \, \text{cm} \times 9 \, \text{cm} = 27 \, \text{cm}^2\)
2. \(24 \, \text{cm} \times 42 \, \text{cm} = 1008 \, \text{cm}^2\)
3. \(5 \, \text{cm} \times 35 \, \text{cm} = 175 \, \text{cm}^2\)

The areas are:

• First rectangle: \(27 \, \text{cm}^2\)
• Second rectangle: \(1008 \, \text{cm}^2\)
• Third rectangle: \(175 \, \text{cm}^2\)