I walked to the mailbox

The square door had four corners

I took out a pile of mail and a box

Every letter was rectangular

With four corners and two sides

The box was rectangular

With eight corners and six sides

I piled one hundred letters into a rectangle

I now had a box shaped pile of mail

Their two hundred sides became six

Their four hundred corners became eight

Where did all the missing sides go

Who stole three hundred and ninety two corners

I opened all the mail

Rectangular papers inside

Soon living in a rectangular trash can

I opened the box

Inside was a ball

With no corners and just one side

The ball was a tight fit in the box

Its one side touching all six sides of the box

If you could inflate the ball

It would eventually touch all the corners inside the box

Its one side would become six sides and eight corners

This is far too many sides and corners

I much prefer the round ball

I am going to start sending people lots of mail

In circular envelopes with just two sides and no corners

The envelopes will all be different sizes

So you can stack them into a ball shaped pile

no more corners