input: Write a function to calculate the distance between two points on a two-dimensional plane using the Euclidean distance formula. The function should take in four parameters: x1, y1 (the coordinates of the first point) and x2, y2 (the coordinates of the second point). The function should return the distance as a float.
  
  
  assert calculate_distance(3, 4, -9, -2) == 13.892443989449804
  assert calculate_distance(0, 0, 3, 4) == 5.0
  assert calculate_distance(-2, -4, -1, -1) == 3.1622776601683795
  
output: def calculate_distance(x1, y1, x2, y2):
      return ((x2 - x1) ** 2 + (y2 - y1) ** 2) ** 0.5