Answer:
What can be measured but has no length, width or height?
Long and thin, red within, with a nail at the end.
What kind of nail can be grown?
In birth I spring forth, in life I unfold. In death I wilt and die, but rebirth restores all.
They can be long or short; they can be grown or bought; they can be painted or left bare; they can be round or square.
It is something you will never see again.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?