Calculate Hypotenuse of Right-angled Triangle.js

/*
Description:
To solve this Kata, complete the function, calculateHypotenuse(a,b), which will return the length of the hyptenuse for a right angled triangle with the other two sides having a length equal to the inputs. More details:

The returned value should be a number rounded to three decimal places
An error (ArgumentException in C#) should be thrown if an invalid input is provided (inputs should both be numbers that are above zero)
calculateHypotenuse(1,1); // returns 1.414
calculateHypotenuse(3,4); // returns 5
calculateHypotenuse(-2,1); // throws error
calculateHypotenuse("one", "two"); // throws error
For more information on the hypotenuse, visit: http://en.wikipedia.org/wiki/Hypotenuse
*/

function calculateHypotenuse(a,b){
  if (typeof a !== 'number'||typeof b !== 'number') throw new Error('Not a Number')
  if (isNaN(a)||isNaN(b)) throw new Error('Not a Number')
  if (a<0||b<0) throw new Error('Less than 0')
  return Math.hypot(a,b).toFixed(3)
}