Day 1 - 10DaysOfJavaScript

/**
 *   Calculate the area of a rectangle.
 *
 *   length: The length of the rectangle.
 *   width: The width of the rectangle.
 *   
 *  Return a number denoting the rectangle's area.
 **/
function getArea(length, width) {
    let area;
    // Write your code here
    area = length * width;
    return area;
}

/**
 *   Calculate the perimeter of a rectangle.
 *  
 *  length: The length of the rectangle.
 *   width: The width of the rectangle.
 *   
 *  Return a number denoting the perimeter of a rectangle.
 **/
function getPerimeter(length, width) {
    let perimeter;
    // Write your code here
    perimeter = 2 * (length + width);
    return perimeter;
}

/*
 * Create the function factorial here
 * Recursion: To call itself is called recursion.
 */
function factorial(n) {
    if (n === 0) {
        return 1;
    }
    return n * factorial(n - 1);
}

function main() {
    // Write your code here. Read input using 'readLine()' and print output using 'console.log()'.
    let r = readLine();
    const PI = Math.PI;
    // Print the area of the circle:
    console.log(PI * (r * r) );
    // Print the perimeter of the circle:
    console.log(2 * PI * r);
}