dif = 6 (slider from 0 to 8, step 0.1)
A = Point(xAxis)
B: -(A)
D = Point(Circle[B, dif])
difK = Segment(B, D)
d = Line(B, D)
b = Segment(A, D)
c = LineBisector(b)
C = Intersect(c, d)
poly1, c_1, a_1, d_1 = Polygon(A, D, C)