# JavaScript: Calculate the area and perimeter of a circle

## JavaScript Object: Exercise-9 with Solution

Write a JavaScript program to calculate the area and perimeter of a circle. Create two methods to calculate the area and perimeter. The radius of the circle will be supplied by the user.

JavaScript: Area and circumference of a circle

In geometry, the area enclosed by a circle of radius r is πr2. Here the Greek letter π represents a constant, approximately equal to 3.14159, which is equal to the ratio of the circumference of any circle to its diameter.

The circumference of a circle is the linear distance around its edge. Why is the area of a circle of a circle pi times the square of the radius? Sample Solution: -

HTML Code:

``````<!DOCTYPE html>
<html>
<meta charset="utf-8">
<title>Area and Perimeter of a circle</title>
<body>
</body>
</html>
```
```

JavaScript Code:

``````function circle(radius)
{
// area method
this.area = function ()
{
};
// perimeter method
this.perimeter = function ()
{
};
}
var c = new circle(3);
console.log('Area =', c.area().toFixed(2));
console.log('perimeter =', c.perimeter().toFixed(2));
```
```

Sample Output:

```Area = 28.27
VM1407:17 perimeter = 18.85
```

Flowchart: Live Demo:

See the Pen javascript-object-exercise-9 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

What is the difficulty level of this exercise?

﻿

Inviting useful, relevant, well-written and unique guest posts