Square

 In school, in math, I learned a square

Had equal sides, so it was fair

To see it not at all the same

As shapes by any other name.

A rectangle was different since

Two sides were shorter, glaring hints 

That it could never be a square;

Inside my brain, that fact is there.

Today, though, in a class on Zoom,

I found out I cannot presume

That what I learned is still correct;

Somehow, the dots do not connect.

I’d helped my grandson with his math

And led him down the wrong-choice path

For rectangles included squares 

When counting - caught me unawares!

Now math is not my strength, but still, 

To alter what I’d mastered will

Into my credence place a dent -

At least in rhyme I get to vent!