Triangles are made up

I only had failing rule breaking left to do

Before I could boast the full collection

 

Fail to do one

Fail to do two

Fail to fail three

 

I failed to follow the example

Then, I failed to learn from failure

And third failing to make some point out of failing

I could have been perfect

I could have learnt how to be perfect

Or thirdway taught a new perfection altogether

 

But boast of triangle instead

Collection without disagreement

Sailing facewards into fourth following

Another example of one of the many shapes

Although, itself, not taught

 

Not in the teaching

Will not teach itself

Failure of failure to be anything else

 

With all three parts imperfect row

I boast something that cannot be learnt.