Any Two Sides of a Triangle In And Then it happened by Ken Langsbury A rip-off from Bernard Miles.  I put the last line in just to show that country folk do know a thing or two - apologies for that.

I was building the hay-rick, and I was sickle-ing these cross-ties on the top corners to hold them in, like.  And this old archeologist feller was walking by - he had some young student fellers with him, about forty-five.  "Do you know what you've done?" he says.  I says, "No, Sir."  He says, "You've built a triangle."  I says "Have I?  I didn't know."  He says, "That's indestructible, that is.  If anybody ever tries to catch you out, just you tell them that any two sides of a triangle is together greater than the third."
Couple of days after that I was caught taking a rabbit out of one of my snares, and had to go up before the Magistrate.  "Anything to say?" he says.  I says, "Yes, Sir.  Any two sides of a triangle is together greater than the third."  That had him!  He didn't know what to do.  He had to ask the Clerk.  They had their heads together for about ten minutes.  Then he says, "Five shillings."  I reckon they'd have made that a Pound if I hadn't knowed that.
And I tells this here archeologist feller a few days later, and he laughed.  He said "I can see I'll have to tell you all about the square on the pythagor-arse."  I says, "Aye", I says, "And e=mc2.  That must be relevant!"  "Aha!" says all the students, "That's one up to the worker!"