No. All non-metals are not non-magnetic.just like hydrogen which is a non-metal but it is a diamagnetic...another example of oxygen, which is a non-metal but it is paramagnetic...and there are alot...
a rectangle is a 4 sided polygon where all the angles are right angles and the opposite sides haveequal length. So a square is a rectangle. But take a rectangle that meets the definition I gave and...