пример с картинки:
a = [(0,0),(3,5),(-2,2)]
b = [(2,0),(4,2),(-1,5)]
print(clip(a, b))
print(calcArea(clip(a,b)))

cтресс тест:
a = [[50,150],[200,50],[350,150],[350,300],[250,300,],[200,250],[150,350],[100,250],[100,200]]
b = [[100,100],[300,100],[300,300],[100,300]]
print(clip(a, b))
print(calcArea(clip(a,b)))