Question

Find the area \(A\) of a rectangle with length 9 centimeters and width 4 centimeters.

Short answer

The area is 36 square centimeters.

Step-by-step solution

- Identify Given Values

The length of the rectangle is given as 9 centimeters and the width is given as 4 centimeters.

- Write Down the Area Formula

The area of a rectangle can be found using the formula: \[ A = \text{length} \times \text{width} \]

- Substitute the Given Values into the Formula

Substitute the given length (9 cm) and width (4 cm) into the area formula: \[ A = 9 \text{ cm} \times 4 \text{ cm} \]

- Calculate the Area

Multiply the length by the width to find the area: \[ A = 9 \text{ cm} \times 4 \text{ cm} = 36 \text{ cm}^2 \]

Key concepts

rectangle area formula

To find the area of a rectangle, you use a simple mathematical formula. The area is calculated by multiplying the length of the rectangle by its width. The formula is written as: \[ A = \text{length} \times \text{width} \]This formula applies to all rectangles, regardless of their size.
For example, if you have a rectangle with a length of 9 centimeters and a width of 4 centimeters, the area can be calculated as follows:
\[ A = 9 \text{ cm} \times 4 \text{ cm} \] \[ A = 36 \text{ cm}^2 \] Understanding this formula is essential for solving many geometry problems. Anytime you need to find the space inside a rectangle, use this formula.

geometry

Geometry is the area of mathematics that deals with shapes, sizes, and the properties of space. It includes studying various figures like circles, triangles, and rectangles.
In geometry, a rectangle is a four-sided figure with opposite sides that are both equal and parallel. This means each rectangle has two lengths and two widths. Other important concepts you might learn in geometry include:

• Perimeter: The total distance around the edge of a rectangle.
• Surface Area: The total area covered by the surface of a 3D figure.
• Volume: The amount of space inside a 3D figure.

Analyzing a rectangle's area helps us understand space and dimensions better, which is useful in everyday tasks like arranging furniture or designing a room.

basic multiplication

Multiplication is one of the fundamental operations in math. It allows you to calculate the total of one number added to itself a certain number of times.
For example, multiplying 9 by 4 means adding 9 four times (9 + 9 + 9 + 9). This is useful for finding the area of a rectangle because you need to multiply the length by the width.
In our rectangle example, multiplying the length (9 cm) by the width (4 cm) gives us: \[ 9 \times 4 = 36 \] This tells us that the area of the rectangle is 36 square centimeters. Multiplication is not just used in geometry. It is also essential in everyday life for things like calculating total costs, figuring out quantities, and understanding growth rates.