code: def calculate_area_of_polygon(polygon):
      n = len(polygon)
      prev = polygon[-1]
      area = 0
  
      for curr in polygon:
          area += (prev[0] + curr[0]) * (prev[1] - curr[1])
          prev = curr
  
      return abs(area / 2)
  
label_desc: Use image node_id 1 for calling a global function with example usage: calculate_area_of_polygon(polygon) and returns: abs