how do I get angle of a triangle not right angled when I know three sides
\(Cosine \ set\)
\(a^2=b^2+c^2-2bc\ cos\alpha\)
\(\alpha=arccos\frac{b^2+c^2-a^2}{2bc}\)
\(\beta=arccos\frac{a^2+c^2-b^2}{2ac}\)
\(\gamma=arccos\frac{a^2+b^2-c^2}{2ab}\)
!