If you think this riddle plain, then click the title and leave your comment.

I am quite plane a figure, bound

By one line that depicts a crown

That dies a meter straight across, sir,

Come and fence, the line you spurred,

Egyptian Ra, Roman Deus,

Half when they together plays.

'You aren't such plane a figure. You're exquisitely unique.'
'Ha, well you flatter me.'

Riddle Answer A Circle

Riddle Explanation

I am quite plane a figure, bound by one line - 'a plane figure bound by one line', Euclid, Elements Book 1.

that dies a meter straight across, sir, come and fence, the line you spurred,
Egyptian Ra, Roman Deus, half when they together plays - key words include; diameter, circumference, and radius.