Where are the hinges on your nearest door?
Yes, durr, they're on the side opposite to the handle, but how are they spaced? Is there an equal gap above the top of the top hinge, and below the bottom of the bottom hinge?
There isn't always.
Where else might you find a hinge?
Boxes have them:
and some old phones:
This is the Cutty Sark's rudder hinge:
and how about these hinges?
Stamps can be stuck into albums with them:
Even some snake fangs teeth are hinged (but I thought that perhaps you'd rather not see a photo of that).
Even your own jaws have a hinge joint, if not an actual hinge.
So how many hinges can you spot without moving?
Spot the Frippet: hinge. This word appeared in English in the 1200s, and is perhaps something to do with the Dutch henghe, which means hook or handle. Old English has a word hangian, to be suspended, which isn't a million miles away, too.