I am totally new in beamer.
I have a question about positioning formulas over a Figure in beamer.
Previously, I was preparing my presentations with Power Point. In Power Point I could write a formula in box, then position it by mouse and if some part of it was under an image, I could simply bring it front of the image and then remove the box filling colour so the image under the formula box can also be seen.
In beamer my figures are included by \input in figure environment like:
\begin{figure}[H]
\centering
\scalebox{0.29}{\input{\MyTikZPath/Sphere.tex}}
\captionsetup{justification=centering}
\caption{Sample Sphere}
\label{fig-1}
\end{figure}
and my equations are written in alignat environment like:
\begin{alignat}{3}
AAA &= yy, \quad & a &= C, \quad & m &= C, \nonumber \\
%
B &= yyyyyyy, \quad & bbcd &= A+B, \quad & n &= A+B, \nonumber\\
%
CCCCCCCC &= T, \quad & c &= BBBBBBB \quad & ddddd &= BBBBBBB \nonumber
\end{alignat}
My question are:
1- Is there any box so I can write the formulas in it and then position it freely (e.g. by absolute coordinates from bottom left corner of the slide)?
2- If there is such a box, can I overlap some part of it over a figure and bring it front of the figure?
3- Is it possible to remove the box filling colour, so everything behind it can be seen?
(Please Note that I want to do all in beamer and I do not want to edit Tikz files)

overlay,remember picturetikzpicture. Unfortunately, you only post fragments, not many will know the contents ofSphere.tex. – Jan 29 '20 at 18:45textpospackage, that work very well in beamer. – vi pa Jan 29 '20 at 18:50