JS Bin// source https://jsbin.com/wuvogusolo

jsbin.wuvogusolo.js

'use strict';

var getCircunference = function getCircunference(radius) {
  return Math.round(2 * 3.14 * radius);
};

var promiseFunction = function promiseFunction(radius) {
  return new Promise(function (resolve, reject) {
    var response = getCircunference(radius);
    if (!isNaN(response)) {
      resolve(response);
    } else {
      reject('not a number');
    }
  });
};

promiseFunction(90).then(function (sai) {
  return console.log('Circunference is: ', sai);
})['catch'](function (error) {
  return console.log('ERROR: ', error);
});

promiseFunction('hellow').then(function (pablo) {
  return console.log('Circunference is: ', pablo);
})['catch'](function (error) {
  return console.log('ERROR: ', error);
});