Cambia la orientación 
del plano 
con β
y anima

α = 0.5235987755982988 rad (slider from 10° to 45°, step 5°)
hcon = 5 (slider from 1 to 5)
β = 1.5707963267948966 rad (slider from 0° to 90°, step 5°)
t = 2.73 (slider from -3 to 3)
O: (0, 0, 0)
vj: (0, 0, 1)
f = Line(O, vj)
C1: (0, 0, hcon)
C2: (0, 0, (-hcon))
rcon: (hcon * tan(α))
np: (0, (-cos(β)), sin(β))
g = Line(O, np)
Q: (0, ((-t) * cos(β)), (t * sin(β)))
p = OrthogonalPlane(Q, np)
a, c, b = Cone(C1, O, rcon)
d, e, h = Cone(C2, O, rcon)
k = IntersectPath(p, a)
A, B, C, D = Corner(k)
q = IntersectPath(p, d)
E, F, G, H = Corner(q)
A1: (0, rcon, hcon)
A2: (0, (-rcon), hcon)
A3: (0, (-rcon), (-hcon))
A4: (0, rcon, (-hcon))
i = Segment(A1, A3)
j = Segment(A2, A4)
l = Line(O, A1)
γ = Angle(l, f)