The transpose of a matrix A denoted by A T A A A A tr t A or A t may be constructed by any one of the following methods. That said if it is genuinely considered off-topic by enough Im happy to remove it of course but put forth that the reason I landed here that this symbol comes highly recommended on many LaTeX pages as a transpose symbol puts it into the TeX context for some many of us I guess. List of LaTeX mathematical symbols.
Simple ordinary noun 11 Latin letters and Arabic numerals 12 Greek letters 13.
This is not a comprehensive list. Reflect A over its main diagonal which runs from top-left to bottom-right to obtain A T. Characters from the ASCII character set can be used directly with a few exceptions pound sign backslash. Open an example in Overleaf.