What is the unit of measure for PowerPoint slides using VBA?
Pardon the pedanticism, but an inch is exactly 72 points, at least as far as PowerPoint and pretty much any digital system is concerned.
Before computers took over, "about" did indeed apply. All the more so because there were several different "standard" definitions of the point.
http://en.wikipedia.org/wiki/Point_(typography)
AAMOF, at one ... er ... point, Microsoft redefined the cm (2.4 to the inch instead of 2.54) to suit its own purposes, leading to confusion when people in the metric climes precisely specified measurements in PowerPoint then found out that things didn't print at the expected size.
They fixed this in PPT 2002, but I'd be there are still files floating around that, when opened in current versions of the app, show odd page sizes.