I gave a talk to my Astronomy club a couple of years ago illustrated with astronomy fact pages from comics but they were all from S.A. titles and some old British comics. You've started me looking through my small but (not quite perfectly formed) G.A collection. Not a sausage so far.
Whoops, just found something. But this example is facts as part of an ad. In the U.S.Royal ads, he explained to his pals how things worked. In Sensation #66 for example, he describes how a jet engine works. Also in the same issue, the Wheaties ad. has sporting facts about Del Ennis, champion rookie of 1946.
Delving further back, Feature Funnies had a few "Strange as it Seems" pages in many issues (I think) which shared odd facts with the reader. In #8 for example there's mention of Edison suing for 4 m Dollars, a 3 ft. Chinese burning glass, some wifie who had read the new testament 125 times and lots more. There's also a "Modern Planes" page. In this issue it's a sub chaser.
Gosh, you've got me started now. If you are interested, some long running British storypapers had fact pages as the front page. Here's a link to a page with Rover covers, you'll see what I mean:-
http://www.kellyscomics.com/rover-comics.php