calculate polygon area

polygonArea.ts

function polygonArea(points: { x: number; y: number }[]) {
  let i = 0;
  let s = 0;
  while (points[i + 1]) {
    const p1 = points[i];
    const p2 = points[i + 1];
    s += p1.x * p2.y - p2.x * p1.y;
    i += 1;
  }
  return Math.abs(s / 2);
}