The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?

Can you quickly find which two matchstick figures are identical?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

Can you count the number of triangles in the given figure?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

Alex is stranded on an island covered in forest.
One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.

There are cliffs around the island, so he cannot jump off.

How can the Alex survive the fire? (There are no buckets or any other means to put out the fire)

The centre of the third figure is empty. What digit should fit inside?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.