# 2.5. Studio: Area of a Circle¶

Get cosy with Java syntax by writing a console program that calculates the area of a circle based on input from the user.

Since you’re still new to Java and IntelliJ, we’ll provide some extra direction the first few coding exercises.

First, make a new folder, or package, to hold your studio exercises. Create a new package named `org.launchcode.java.studios.areaofacircle` by right-clicking (or ctrl-clicking for some Mac users) on the `src` directory in `java-web-dev-exercises` and selecting New > Package. Be sure to enter the full name, or your package won’t be created in the correct location.

Create your class in the `java-web-dev-exercises` project within the package `org.launchcode.java.studios.areaofacircle` by right-clicking/ctrl-clicking on the `studios.areaofacircle` package/folder and selecting New > Java Class. Enter the name `Area`. Select the option to add the file to Git when the window appears.

Write a class, `Area`, that prompts the user for the radius of a circle and then calculate its area and print the result.

Tip

Recall that the area of a circle is `A = pi * r * r` where `pi` is 3.14 and `r` is the radius.

Note

Unlike some other languages, Java does not have an exponent operator.

Here’s an example of how your program should work:

```Enter a radius: 2.5
The area of a circle of radius 2.5 is: 19.625
```

1. What data type should the radius be?

2. What is the best way to get user input into a variable `radius` of that type?

Warning

Be sure to create a `main` method to place your code within. It’s signature must be:

```public static void main(String[] args)
```

Add a second Java file to your program to delegate the area calculation away from the printing task.

1. Add a new class in your `studios.areaofacircle` package called `Circle`.

2. Create a method called `getArea` inside of `Circle` that takes a Double `radius` as its only parameter and returns another `Double`, the result of the area calculation.

```public static Double getArea(Double radius) {
3. Back in `Area`, replace your area calculation line with a call to `Circle.getArea()`.
Check out the `HelloMethods` and `Message` example from Static Methods for a reference on how to use a class from another file.