code: function trianglesPerArc (angle, width) {
      if (angle < 0) {
          angle = -angle;
      }
  
      var numTriangles = (width > 2 * MIN_FAN_WIDTH) ? Math.log2(width / MIN_FAN_WIDTH) : 1;
      return Math.ceil(angle / Math.PI * numTriangles);
  }
docs: Calculate number of triangles for a fan given an angle and line width