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Last updated on September 15, 2025
Area is the space inside the boundaries of a two-dimensional shape or surface. There are different formulas for finding the area of various shapes/figures. These are widely used in architecture and design. In this section, we will find the area of different shapes.
A shape is a two-dimensional figure defined by its boundaries. The area of a shape is the total space it encloses.
There are specific formulas to calculate the area of different shapes like squares, rectangles, triangles, circles, and more.
Each shape has its own formula for calculating area. Here are a few key formulas:
1. Square: Area = side × side
2. Rectangle: Area = length × width
3. Triangle: Area = 1/2 × base × height
4. Circle: Area = π × radius²
The formulas are derived based on the properties of each shape. For instance, a square's area is calculated by squaring the length of its side, a rectangle's by multiplying its length and width, and a circle's by multiplying π (pi) with the square of its radius.
We can find the area of shapes using various methods depending on the shape:
Using Side Lengths: For squares and rectangles, use the lengths of the sides.
Using Base and Height: For triangles and parallelograms, use the base and height.
Using Radius: For circles, use the radius.
Let's discuss some examples:
1. Square: If the side length is 5 cm, the area is 5 × 5 = 25 cm².
2. Rectangle: With a length of 8 cm and width of 3 cm, the area is 8 × 3 = 24 cm².
3. Triangle: With a base of 6 cm and height of 4 cm, the area is 1/2 × 6 × 4 = 12 cm².
4. Circle: With a radius of 7 cm, the area is π × 7² = approximately 153.94 cm².
We measure area in square units. The measurement depends on the system used:
In the metric system, the area is measured in square meters (m²), square centimeters (cm²), and square millimeters (mm²).
In the imperial system, the area is measured in square inches (in²), square feet (ft²), and square yards (yd²).
Specific shapes have unique properties that affect how their area is calculated.
Consider these variations:
1. Circle: The formula uses π, a constant approximately equal to 3.14159.
2. Triangle: Besides base and height, you can also use Heron's formula when all sides are known.
3. Parallelogram: Similar to a rectangle, but height is the perpendicular distance from the base.
4. Trapezoid: Uses a different formula: Area = 1/2 × (base₁ + base₂) × height.
To ensure accuracy when calculating the area of shapes:
It is common for mistakes to occur when finding the area of shapes. Here are some common mistakes and how to avoid them:
A rectangular garden has a length of 10 m and a width of 5 m. What is the area?
The area is 50 m².
The area of a rectangle is calculated as length × width.
Here, the length is 10 m, and the width is 5 m.
Therefore, the area = 10 × 5 = 50 m².
Find the area of a triangle with a base of 12 m and height of 9 m.
The area is 54 m².
The area of a triangle is calculated as 1/2 × base × height.
Here, the base is 12 m, and the height is 9 m.
Therefore, the area = 1/2 × 12 × 9 = 54 m².
A circle has a radius of 3 cm. What is its area?
The area is approximately 28.27 cm².
The area of a circle is calculated as π × radius².
Here, the radius is 3 cm.
Therefore, the area = π × 3² = π × 9 ≈ 28.27 cm².
If a square has a side length of 7 cm, what is its area?
The area is 49 cm².
The area of a square is calculated as side × side.
Here, the side length is 7 cm.
Therefore, the area = 7 × 7 = 49 cm².
A parallelogram has a base of 8 m and height of 4 m. What is its area?
The area is 32 m².
The area of a parallelogram is calculated as base × height.
Here, the base is 8 m, and the height is 4 m.
Therefore, the area = 8 × 4 = 32 m².
Seyed Ali Fathima S a math expert with nearly 5 years of experience as a math teacher. From an engineer to a math teacher, shows her passion for math and teaching. She is a calculator queen, who loves tables and she turns tables to puzzles and songs.
: She has songs for each table which helps her to remember the tables