Can you find approximately the center of this stretch reflection

A = (0.4, -0.14)
B = (5.58944564012756, 2.5616754406349687)
C = (8.844524605842263, 0.39162279682517287)
D = (4.30875349022181, -4.994115816381539)
poly1, d, b, c = Polygon(B, C, D)
B' = Rotate(B, 34°, A)
C' = Rotate(C, 34°, A)
D' = Rotate(D, 34°, A)
poly1', d', b', c' = Polygon(B', C', D')
E = (6.1, 4.5)
F = (0.28, -3.16)
f = Line(E, F)
B'_1 = Mirror(B, f)
C'_1 = Mirror(C, f)
D'_1 = Mirror(D, f)
poly1'_1, d'_1, b'_1, c'_1 = Polygon(B'_1, C'_1, D'_1)
G = Dilate(B'_1, 0.56, F)
H = Dilate(C'_1, 0.56, F)
I = Dilate(D'_1, 0.56, F)
poly2, i, g, h = Polygon(G, H, I)