input: Write a function to calculate the distance between two points on a two-dimensional plane given their coordinates (x1, y1) and (x2, y2). The function should return the distance as a float. 
  
  assert calculate_distance(3, 4, -9, -2) == 13.0
  assert calculate_distance(0, 0, 0, 1) == 1.0
  assert calculate_distance(-2, -1, 1, 5) == 5.0
  assert calculate_distance(10, 5, 3, -2) == 9.9
  assert calculate_distance(0, 0, 0, 0) == 0.0
output: def calculate_distance(x1, y1, x2, y2):
      return ((x2 - x1) ** 2 + (y2 - y1) ** 2) ** 0.5