Decode the Mnemonic

[Sameer Jamal]

Here is a piece of Mnemonic

"Now I-even I, would celebrate
in rhymes unapt the great
Immortal syracusan rivaled never more,
who in his wonderous lore
Passed on before,
Left men his guidance
How to circle mensurate"

Can you tell what it signifies ?

[kayal cox]

I know this, I know this.
The last line of the mnemonic has the clue

[Mani Ram]

Originally posted by Sameer Jamal:
Here is a piece of Mnemonic

Nice piece of Mnemonic

[Ryan McGuire]

Originally posted by Sameer Jamal:
Here is a piece of Mnemonic

"Now I-even I, would celebrate
in rhymes unapt the great
Immortal syracusan rivaled never more,
who in his wonderous lore
Passed on before,
Left men his guidance
How to circle mensurate"

Can you tell what it signifies ?

A similar mnemonic was the Final Jeopardy clue two or three weeks ago.

[Stan James]

My dad had another for the same value but it was more, um, ribald. The other day I incorrectly posted that it used the first letter of each word, but seeing this I realize it used the same trick as this one. I regret I never learned it from him.

[Sameer Jamal]

Its pie value upto 7 decimal places