nodeslip3a

 Slip3a.js

var circle_area = require('./circle');

var circle_circumference = require('./circle');

console.log("Area of circle is:" + circle_area.area());

console.log("Circumference is:" + circle_circumference.circumference());

circle.js

exports.area = function(){

    r = 3, pi = 3.14;

    return pi*(r*r);

};

exports.circumference = function(){

    r = 3, pi = 3.14;

    return 2*pi*r;

}; 

//with user input

Slip3a.js

var areacircum = require('./circleexp');

var rl = require('readline').createInterface({

    input: process.stdin,

    output: process.stdout

  });

  rl.question('Enter The Number : ', r => {

    var ans=areacircum(r);

    console.log(`Your Answer Is : ${ans}`);

    rl.close();

});

Circleexp.js

module.exports = function areacircum(r){

    pi = 3.14;

    return [pi*(r*r) , 2*pi*r];

};