Some of my websites pages are different format than the default theme format

Two (to be exact) of my pages are completely different formatting, mainly font sizing and spacing within the page. To be honest, I like the different format, but I want it all to coincide with one another.

I would either like to keep the format that has changed or just leave it all at the default format, but first the issue at hand: locate the problem. So if anyone has any idea or has had this happen themselves, any help would be greatly appreciated!

Cheers!