code: def rotateX(self, angle):
          
          rad = angle * math.pi / 180
          cosa = math.cos(rad)
          sina = math.sin(rad)
          y = self.y * cosa - self.z * sina
          z = self.y * sina + self.z * cosa
          return Point3D(self.x, y, z)
docs: Rotates the point around the X axis by the given angle in degrees.