排列組合與機率統計(10)
Author: 藍邦偉　老師

n = 0 (slider from 0 to 2, step 1)
A = (-2.88, 0.06)
B: A + (0.7, 0)
D: A + (0, 0.5)
C: B + D - A
poly1, a, b, c, d = Polygon(A, B, C, D)