Polygon area

# def area(point1, point2, point3):
#     (x1, y1) = point1
#     (x2, y2) = point2
#     (x3, y3) = point3

#     return abs(x3 * (y1 - y2) + x1 * (y2 - y3) + x2 * (y3 - y1))


if __name__ == "__main__":
    n = int(input())
    points = []
    for i in range(n):
        point = list(map(int, input().split()))
        points.append(point)

    total_area = 0
    for i in range(n):
        j = (i + 1) % n
        total_area += points[i][0] * points[j][1]
        total_area -= points[j][0] * points[i][1]
    print(abs(total_area))

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED