from sprites import * A = (0,0) B = (150,200) C = (250,50) bug = Sprite() bug.pencolor('blue') bug.pensize(4) bug.draw_line(A,B) bug.draw_line(B,C) bug.draw_line(C,A) # 返回三角形的外心(中垂线的交点) D = excenter(A,B,C) bug.goto(D) bug.dot(10,'red') bug.hide()