A = (-2.5934341101454876, -2.7480403551458323, 0)
B = (0.962673017520455, -0.6273985774210686, 0)
C = Point(Circle[Midpoint[A, B], (Distance[A, B] * sqrt(3) / 2), Segment[A, B]])
a, D, facciaABC, facciaACD, facciaABD, facciaBCD, spigoloAC, spigoloAB, spigoloBC, spigoloAD, spigoloCD, spigoloBD = Tetrahedron(A, B, C)
f = OrthogonalLine(D, xOyPlane)
g = OrthogonalLine(A, facciaBCD)
E = Intersect(f, g)
F = Intersect(g, facciaBCD)
b = Sphere(E, F)
t1, f_1, d, e = Polygon(D, E, F)