for-emina.py

class Point:
    def __init__(self, x: float, y: float):
        self.x = x
        self.y = y

    def __sub__(self, other: 'Point') -> 'Point':
        return Point(self.x - other.x, self.y - other.y)


def skew_product(a: Point, b: Point) -> float:
    return a.x * b.y - a.y * b.x


def point_in_triangle(p: Point, a: Point, b: Point, c: Point) -> bool:
    s1 = skew_product(p - a, b - a)
    s2 = skew_product(p - b, c - b)
    s3 = skew_product(p - c, a - c)
    return s1 >= 0 and s2 >= 0 and s3 >= 0 \
        or s1 <= 0 and s2 <= 0 and s3 <= 0


def triangle_exists(a: Point, b: Point, c: Point) -> bool:
    return abs(skew_product(b - a, c - a)) > 1e-9


def main():
    points = [Point(*list(map(float, input(f'Input x{i} y{i}: ').split()))) for i in range(4)]

    for i in range(4):
        ip, ia, ib, ic = i, (i + 1) % 4, (i + 2) % 4, (i + 3) % 4
        p, a, b, c = points[ip], points[ia], points[ib], points[ic]
        if triangle_exists(a, b, c) and point_in_triangle(p, a, b, c):
            print(f'Point (x{ip}, y{ip}) is in triangle (x{ia}, y{ia}), (x{ib}, y{ib}), (x{ic}, y{ic})')
            break
    else:
        print('There is no point in triangle')


if __name__ == '__main__':
    main()