Aspect Ratio Calculator

function resize(width, height, newWidth) {
  const ratio = height / width;
  return { width: newWidth, height: Math.round(newWidth * ratio) };
}

function gcd(a, b) {
  return b ? gcd(b, a % b) : a;
}

function aspectRatio(w, h) {
  const g = gcd(w, h);
  return `${w/g}:${h/g}`;
}