Les hauteurs BB' et CC' sont égales.
Que peut-on en déduire ?

preuve4

preuve4b

preuve4c

preuve4d

C = (4.48, -0.4)
B = (-0.38, -0.38)
a = Segment(B, C)
b = LineBisector(a)
A = Point(b)
c = Segment(A, B)
d = Segment(A, C)
f = Line(B, A)
g = Circle(C, B)
U = Intersect(g, d, 1)
h = Circle(B, Segment[A, U])
k = Circle(C, Segment[A, U])
e = OrthogonalLine(B, d)
i = OrthogonalLine(C, c)
C' = Intersect(i, c)
B' = Intersect(e, d)
α = Angle(B, B', C)
β = Angle(B, C', C)
j = Segment(B, B')
l = Segment(C, C')
n = false
D = Midpoint(a)
E = (1.86, 6.78)
m = Line(D, E)
F = Point(a)
G = Point(m)
H = (2.4, 0)
p = Segment(G, H)
q = Segment(H, F)
r = Circle(D, B)
s = Circle(C, C')
t = Circle(B, B')
o = false
u = false
C'' = Intersect(r, s, 2)
v = false