function pythagorean_theorem(x, y) {  
      if ((typeof x !== 'number') || (typeof y !== 'number'))   
    return false;   
            return Math.sqrt(x * x + y * y);  
        }  
      
    console.log(pythagorean_theorem(2, 4));  
    console.log(pythagorean_theorem(3, 4));