6 cm

8 cm

A = (2, 1)
B = (10, 1)
C = (2, 7)
t1, b, c, a = Polygon(C, A, B)
B' = Dilate(B, 1 / 40, A)
poly1, f, g, h, i, D, E = Polygon(A, B', 4)
F = Point(a)
j = Line(F, c)
k = Line(F, b)
G = Intersect(j, b)
H = Intersect(c, k)
u = Vector(H, F)
poly1' = Translate(poly1, u)
v = Vector(G, F)
poly1'_{1} = Translate(poly1, v)
l = Segment(F, H)
m = Segment(F, G)
n = Segment(G, H)