Rust program to calculate the area of the circle

Input radius of the circle, find the area of the circle using Rust program.
Last Updated : September 26, 2021

Problem Statement

Here, we will read the radius from the user and calculate the area of the circle.

Program/Source Code

The source code to calculate the area of the circle is given below. The given program is compiled and executed successfully.

// Rust program to calculate the area of circle

use std::io;

fn main() {
    let mut radius:f32 = 0.0;
    let mut area:f32 = 0.0;
    let mut input = String::new();
    
    println!("Enter radius: ");
    io::stdin().read_line(&mut input).expect("Not a valid string");
    radius = input.trim().parse().expect("Not a valid number");

    //Caculate the area of circle
    area = 3.14 * radius * radius;
 
    println!("Area of circle: {}",area);
}

Output

RUN 1:
Enter radius: 
1.2
Area of circle: 4.5216007

RUN 2:
Enter radius: 
5.15
Area of circle: 83.28066

RUN 3:
Enter radius: 
10
Area of circle: 314