排列組合與機率統計(6)
Author: 藍邦偉　老師

n = 0 (slider from 0 to 2, step 1)
A = (-2.76, 3.88)
B: A + (0.4, 0)
C: A + (0, 0.5)
D: B + C - A
poly2, a_1, b_1, d_1, c_1 = Polygon(A, B, D, C)