Change the Speed slider to animate. What can be said about the Yellow Triangle? What is the same what is different?

J Robinson 2010

Show Altitude

α = 6.014404602372459 rad (slider from 0 to 6.283185307179586, step 0.0017453292519943296)
A = (-3, -5)
B = (15, -5)
a = Line(A, B)
b = OrthogonalLine(A, a)
c = OrthogonalLine(B, a)
C = Point(b)
d = OrthogonalLine(C, b)
D = Intersect(c, d)
poly1, a_1, c_1, d_1, b_1 = Polygon(A, C, D, B)
E = Midpoint(C, D)
F = Midpoint(C, B)
E' = Rotate(E, -(α), F)
e = Line(F, E')
G = Intersect(c_1, e)
poly2, b_2, a_2, g = Polygon(A, G, B)
H = Intersect(a_1, e)
poly3, b_3, d_2, h = Polygon(D, H, B)
β = Angle(D, F, E)
γ = Angle(B, F, E)
I = Intersect(b_1, g)
J = Intersect(e, g)
poly4, d_3, c_2, j = Polygon(C, J, D)
δ = Angle(A, F, E)
K = Intersect(e, h)
poly5, a_3, c_3, k = Polygon(C, K, A)
ε = Angle(C, F, E)
Speed = 0 (slider from 0 to 2, step 0.1)
f = OrthogonalLine(G, b_1)
i = OrthogonalLine(H, d_1)
l = OrthogonalLine(J, c_1)
m = OrthogonalLine(K, a_1)
L = Intersect(f, b_1)
M = Intersect(l, c_1)
n = Segment(G, L)
p = Segment(J, M)
N = Intersect(i, d_1)
O = Intersect(a_1, m)
q = Segment(O, K)
r = Segment(N, H)
o = false