Area and Perimeter of Rectangle

Program to calculate area and perimeter of a rectangle

BeginnerTopic: Basic Programs

JavaScript Area and Perimeter of Rectangle Program

This program helps you to learn the fundamental structure and syntax of JavaScript programming.

// Formula: Area = length × width
// Formula: Perimeter = 2 × (length + width)

let length = 10;
let width = 5;

let area = length * width;
let perimeter = 2 * (length + width);

console.log("Rectangle Dimensions:");
console.log("Length:", length);
console.log("Width:", width);
console.log("Area:", area, "square units");
console.log("Perimeter:", perimeter, "units");

// Function version
function rectangleArea(length, width) {
    return length * width;
}

function rectanglePerimeter(length, width) {
    return 2 * (length + width);
}

let rectLength = 8;
let rectWidth = 6;

console.log("\nUsing functions:");
console.log(`Area: ${rectangleArea(rectLength, rectWidth)} sq units`);
console.log(`Perimeter: ${rectanglePerimeter(rectLength, rectWidth)} units`);

Output

Rectangle Dimensions:
Length: 10
Width: 5
Area: 50 square units
Perimeter: 30 units

Using functions:
Area: 48 sq units
Perimeter: 28 units

Understanding Area and Perimeter of Rectangle

This program calculates the area and perimeter of a rectangle using geometric formulas.

Rectangle Formulas

Area

: length × width

•Measured in square units

•Represents the space inside the rectangle

Perimeter

: 2 × (length + width)

•Measured in linear units

•Represents the total distance around the rectangle

Example Calculation

For a rectangle with length = 10 and width = 5:

•Area = 10 × 5 = 50 square units

•Perimeter = 2 × (10 + 5) = 2 × 15 = 30 units

Function Approach

Creating separate functions for each calculation:

function rectangleArea(length, width) {
}

function rectanglePerimeter(length, width) {

    return 2 * (length + width);
}

    return length * width;

Benefits:

•Reusable functions

•Clear separation of concerns

•Easy to test

•Can be used independently

Related Shapes

Square

(special rectangle where length = width):

function squareArea(side) {
}

function squarePerimeter(side) {

    return 4 * side;
}

    return side * side; // or side ** 2

Real-world Applications

•Flooring calculations

•Fencing requirements

•Painting area calculations

•Land area measurements

•Construction planning

Input Validation

Always validate inputs:

function rectangleArea(length, width) {
    if (length <= 0 || width <= 0) {
    }

    return length * width;
}

        return "Invalid dimensions";

Let us now understand every line and the components of the above program.

Note: To write and run JavaScript programs, you need to set up the local environment on your computer. Refer to the complete article Setting up JavaScript Development Environment. If you do not want to set up the local environment on your computer, you can also use online IDE to write and run your JavaScript programs.

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