draw an analog clock

function drawClock(radius, hour, minute, second) {
  var canvas = document.getElementById("canvas");
  var ctx = canvas.getContext("2d");
  ctx.clearRect(0, 0, canvas.width, canvas.height);

  var radius = canvas.height / 2;
  ctx.translate(radius, radius);
  radius = radius * 0.90
  drawFace(ctx, radius);
  drawNumbers(ctx, radius);
  drawTime(ctx, radius, hour, minute, second);
}