input: Write a python function to find the total surface area of a rectangular prism.
  assert find_total_surfacearea(2, 3, 4) == 52
  assert find_total_surfacearea(1, 1, 1) == 6
  assert find_total_surfacearea(5, 5, 5) == 150
output: def find_total_surfacearea(length, width, height):
      return 2 * (length * width + width * height + height * length)