Does anyone know the formula to determine the perimeter of a circle? This would be so handy for designing things like Gun barrels, wheels, engines, and anyother cylinders. K'Jev

Dia. of circle I believe the formula is 2 x pi x radius. ( pi = 3.14 ) If I'm wrong, somebody please correct me. John

I've posted this once but it didn't show, so here goes again. Thanks dansls1, that's a better way of saying it. Here is a site to speed up the math..............Circumference of a Circle John

Of the two equations given above, pi X diameter is the correct one for the circumference of a circle. And if you're interested, pi x (radius squared) = area of circle. pi = 3.1417 Bob

Actually Pi is 3.14159 to five decimal points... Terry N and Z scale Old West paper models (free samples) at: paperbeam - virtual paper models

Ermmm..... Did I mention I posted this question since I SUCK at math? Now History, English, Spanish, or Arabic, that's a different story. K'Jev 8) PS: NO WORD PROBLEMS! If God intended numbers to be mixed with letters, we'd be speaking Algebraic. They should stay in separate classrooms where they belong! :thumb:

TexasTubaMan: I'm calling your 14 and raising it to 1,000...:twisted: 1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337867831652712019091456485669234603486104543266482133936072602491412737245870066063155881748815209209628292540917153643678925903600113305305488204665213841469519415116094330572703657595919530921861173819326117931051185480744623799627495673518857527248912279381830119491298336733624406566430860213949463952247371907021798609437027705392171762931767523846748184676694051320005681271452635608277857713427577896091736371787214684409012249534301465495853710507922796892589235420199561121290219608640344181598136297747713099605187072113499999983729780499510597317328160963185950244594553469083026425223082533446850352619311881710100031378387528865875332083814206171776691473035982534904287554687311595628638823537875937519577818577805321712268066130019278766111959092164201989 What ya got?sign1 Terry N and Z scale Old West paper models (free samples) at: paperbeam - virtual paper models