text: function solve(input){
      if (typeof(input) === 'number'){
          return (Math.pow(input, 2) * Math.PI).toFixed(2);
      } else {
          return `We can not calculate the circle area, because we receive a ${typeof(input)}.`
      }
  }
  
  console.log(solve(5));
  console.log(solve('name'));