x1, y1 = 1, 1
x2, y2 = 2, 2
x3, y3 = 3, 3
x4, y4 = 4, 4
is_square = lambda x1, y1, x2, y2, x3, y3, x4, y4: all([abs(__import__('math').hypot(x2 - x1, y2 - y1) - __import__('math').hypot(x3 - x2, y3 - y2)) < 1e-9, abs(__import__('math').hypot(x3 - x2, y3 - y2) - __import__('math').hypot(x4 - x3, y4 - y3)) < 1e-9, abs(__import__('math').hypot(x4 - x3, y4 - y3) - __import__('math').hypot(x1 - x4, y1 - y4)) < 1e-9, abs(__import__('math').hypot(x1 - x4, y1 - y4) - __import__('math').hypot(x2 - x1, y2 - y1)) < 1e-9])
print("Является ли четырехугольник квадратом?", is_square(x1, y1, x2, y2, x3, y3, x4, y4))