input: Write a python function to calculate the total area of a list of rectangles.
  assert calculateTotalArea([[3, 4], [6, 6], [1, 8]]) == 81
  assert calculateTotalArea([[2, 3], [4, 5], [6, 7]]) == 62
  assert calculateTotalArea([[1, 1], [2, 2], [3, 3]]) == 14
output: def calculateTotalArea(rectangles):
      total_area = 0
      for width, height in rectangles:
          total_area += width * height
      return total_area