Primeter
The length of boundary of a closed figure is called peri meter.

Area
The space occupied by the figure is called area.

Perimeter and Area: An Explanation for 7th Class

Introduction:
In mathematics, perimeter and area are two fundamental concepts used to measure and describe geometric shapes. These concepts play a crucial role in various fields such as architecture, engineering, and construction. Understanding the definitions and calculations of perimeter and area is essential for solving geometry problems. Let's explore these concepts in detail.

Perimeter:
The perimeter of a shape refers to the total distance around its outer boundary. It can be thought of as the length of the outline of a shape. The perimeter is measured in linear units such as centimeters, meters, or feet. The formula to calculate the perimeter depends on the shape:

1. Perimeter of a Square: The perimeter of a square is found by multiplying the length of one side by 4.
Perimeter = 4 * side length

2. Perimeter of a Rectangle: The perimeter of a rectangle is calculated by adding the lengths of all four sides.
Perimeter = 2 * (length + width)

3. Perimeter of a Triangle: The perimeter of a triangle is determined by adding the lengths of all three sides.
Perimeter = side1 + side2 + side3

4. Perimeter of a Circle: The perimeter of a circle is known as its circumference. It can be calculated using the formula:
Perimeter = 2 * π * radius

Area:
The area of a shape refers to the amount of space enclosed within its boundaries. It is measured in square units such as square centimeters, square meters, or square feet. The formula to calculate the area also depends on the shape:

1. Area of a Square: The area of a square is determined by multiplying the length of one side by itself.
Area = side length * side length or Area = side^2

2. Area of a Rectangle: The area of a rectangle is found by multiplying its length by its width.
Area = length * width

3. Area of a Triangle: The area of a triangle can be calculated using different formulas depending on the given information. For example, if the base and height are known, the area can be found using the formula:
Area = 0.5 * base * height

4. Area of a Circle: The area of a circle is calculated using the formula:
Area = π * radius^2

Conclusion:
Perimeter and area are important concepts in geometry that help us quantify and describe shapes. The perimeter measures the length of the outer boundary, while the area measures the amount of space enclosed within the boundaries. Understanding the formulas and calculations for perimeter and area allows us to solve various mathematical problems and analyze real-life situations involving shapes. Practice and application of these concepts will further enhance your understanding and problem-solving skills in geometry.