JavaScript Program to Find Area of a Circle

To find area of a circle using JavaScript, we will be using the simple formula: Area = ? × r² where r is the radius and ? is a constant value pi.

In this article, we are having radius of the circle and our task is to find the area of the circle using JavaScript.

Example Calculation

let radius = 10 and ?(pi) = 3.1415926535
Area = ? × r²
Area = 3.1415926535 × 10 × 10
Area = 314.15926535

Steps to Find Area of Circle

• Store the radius of circle and pi value in variables.
• Define a function areaCircle() to calculate the area using the formula.
• The function takes pi and radius as parameters and returns the area.
• Call the function and display the result using console.log().

Using Custom Pi Value

This example demonstrates calculating circle area with a custom pi value.

let radius = 10;
let pi = 3.141592653589793238;

function areaCircle(p, r){
    return p * r * r;
} 

let area = areaCircle(pi, radius);
console.log("The area of the circle is: " + area);

The area of the circle is: 314.1592653589793

Using Math.PI and Math.pow()

In this example, we use Math functions for pi value and to calculate the square of radius using Math.PI and Math.pow() respectively.

let radius = 10;
let pi = Math.PI;

function areaCircle(p, r){
    return p * Math.pow(r, 2);
} 

let area = areaCircle(pi, radius);
console.log("The area of the circle is: " + area);

The area of the circle is: 314.1592653589793

Simplified Approach

Here's a more concise version that directly uses Math.PI:

function calculateCircleArea(radius) {
    return Math.PI * radius * radius;
}

let radius = 7.5;
let area = calculateCircleArea(radius);
console.log(`Circle with radius ${radius} has area: ${area.toFixed(2)}`);

Circle with radius 7.5 has area: 176.71

Comparison of Methods

Practice and learn from a wide range of JavaScript examples, including event handling, form validation, and advanced techniques. Interactive code snippets for hands-on learning.

Conclusion

Calculating circle area in JavaScript is straightforward using the formula ? × r². Use Math.PI for better accuracy and consider toFixed() for formatting decimal places in the output.