is this a bug?
The code:
sage: a
3
sage: b
8
sage: c
7
sage: t = (a*a + b*b - c*c)/(2.0 *a*b)
sage: acos(t)
1.04719755119660
sage: N(acos(t)/pi)
0.333333333333333
sage: gamma = acos(t)
sage: N(gamma/pi)
0.333333333333333
sage: gamma = acos ((a*a + b+b - c*c)/(2.0 *a*b))
sage: N(gamma/pi)
0.666666666666667
sage: version()
'SageMath version 10.0, Release Date: 2023-05-20'
I did not manage to make it show up as code, sorry, but it is code.
the gamma angle of a (3,8,7) triangle is pi/3, not 2pi/3; Sage will give both answers.