同位角，錯角の表示

三角形の内角の和は何度になるでしょう？

補助線の表示

A = (2.48, 3.98)
B = (-1.5, 0.48)
C = (3.32, 0.48)
t1, h, i, k = Polygon(A, C, B)
f = Ray(B, C)
D = Point(f)
g = Segment(C, D)
b = Angle(C, B, A)
c = Angle(A, C, B)
a = Angle(B, A, C)
l = Line(C, k)
E = Point(l)
m = Segment(C, E)
d = Angle(D, C, E)
e = Angle(E, C, A)
n = false
j = false