class Rectangle:
    """ A class representing a rectangle """
    
    def __init__(self, x1, y1, x2, y2):
        self.x1 = x1
        self.y1 = y1
        self.x2 = x2
        self.y2 = y2
        
    def area(self):
        height = abs(self.y2 - self.y1)
        width = abs(self.x2 - self.x1)
        
        return width * height