AB

AC

BC

A = (-6.88, -0.64)
side1length = 6 (slider from 1 to 10, step 1)
B = Point(Circle[A, side1length])
AB = Segment(A, B)
side2length = 7 (slider from 1 to 10, step 1)
side3length = 8 (slider from 1 to 10, step 1)
c = Circle(A, side2length)
d = Circle(B, side3length)
C = Intersect(c, d, 1)
AC = Segment(A, C)
k = Line(A, B)
BC = Segment(C, B)
g = Line(B, C)
D = Midpoint(AB)
E = Midpoint(AC)
DE = Segment(D, E)
α = Angle(A, E, D)
β = Angle(E, C, B)
γ = Angle(E, D, A)
δ = Angle(C, B, D)
ε = Angle(E, D, A)
ζ = Angle(C, B, D)