We answer this question in two parts:
A. What is the version of Pathagoras that is installed on my computer?
Click down the Pathagoras features menu and select Main Menu
Click the About tab (#1 in figure below).
The currently installed version information will be shown in at the right side of the 'About' screen. (#2)
B. And what is the latest version of Pathagoras that has been released?
Click the 'Check for Updates' button (#3 in the figure below).
You can upgrade Pathagoras from the Utilities/Settings|Updates screen. Click here for more information.