> Use of formulae is outside the scope of pure geometry ala Euclidian style.
Like Heron's formula?
> Trigonometry using algebra is part of analytic geometry.
Yes, a part of analytic geometry. Distances and angles are also a part of analytic geometry.
> Explicit use of coordinate system is not essential.
Yes it is. That's literally what analytic geometry (i.e. coordinate geometry) means.