input: Write a function to calculate the distance between two points on a two-dimensional plane. The function should take two tuples representing the points' coordinates (x1, y1) and (x2, y2) and return the distance as a float.
  assert distance_between_points((3, 4), (-9, -2))==13.416407864998739
  assert distance_between_points((0, 0), (1, 1))==1.4142135623730951
  assert distance_between_points((2, 2), (2, 2))==0.0
  assert distance_between_points((-5, -5), (5, 5))==14.142135623730951
output: def distance_between_points(point1, point2):
      x1, y1 = point1
      x2, y2 = point2
      return ((x2 - x1) ** 2 + (y2 - y1) ** 2) ** 0.5