2:20 Talks about ruler on top right isn't there. However i found a video that does explain this ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ljtPtRIyHMk.html Also, its out of date slightly so all you do instead is click on view, click show & ruler. Don't seem like a native English speaker either speaks very slow.