B = (2, 1)
f = Line((0, x(B)), (1, y(B)))
C = (2.3690697674418577, 1.9495042839657282)
g = Line((0, x(C)), (1, y(C)))
A = (1.3422129401329195, 2.210799443553253)
h = Line((0, x(A)), (1, y(A)))
A' = Intersect(f, g)
B' = Intersect(g, h)
C' = Intersect(f, h)
p = FitPoly({A', B', C'}, 2)
coeff = Element(Coefficients[p(x)], 1)
ratio: Area[A, B, C] / Area[A', B', C']