south and north pole
or
left and right hand
or
a girl and a boy
Men and women
-- negative polarity -- positive polarity
in the real world
Roads are an example of intersecting lines in the real world.
metals
If you're referring to chemical polarity, then water is a common polar substance. It's polar because at the particle level, a water molecule has a positive end and a negative end (caused by unshared electrons between hydrogen and oxygen.) As a result, water is able to dissolve many other substances which are also polar (like salt.)
Scales or balances.
l
The Grand Canyon.
normal_distribution
A Jarlid
McDonalds Arches