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By SeraAngel On 03/30/04  

i recently made a round duffle bag and it came out great. i mimicked another bag that i bought but i was so sure that i worked out the measurements. i am now trying to make a few more and they don't seem to match up.

the length of the fabric is 25.5" but my circle that i cut out for the sides doesn't match. does anyone know how to figure out the diameter for this?
i was using a 9" plate as my template but it is now too big.

thanks in advance.

By monstergirl On 03/30/04  

Diameter = the length across the circle (the diameter of your 9" plate is 9 inches) Radius (r) will be half that: 4.5"

Circumference = the measurement around the edge of the circle (where you're trying to sew the bag together) is 2 times 3.14 times the radius (2*Pi*r), or 9*3.14 (if you're using the plate example).

So the length of the side to sew to the round part should be about 28 1/4 inches, plus seam allowance. If you're using the plate example.

If it's another size, I reccomend folding the circle in half, measuring that long flat part, and x by 3.14 to get your measurement (plus seam allowance).

Ha! I defy *anyone* to tell me HS geometry is a waste! LOL


By sewfan On 03/30/04  

To get diameter from the circumference you divide the circumference by pi, so in your case it would be 25.5/3.14 and you'd get 8.12. Your template should then be a circle with a diameter of 8.12".
If you want to use the plate, then do 9 x pi = 28.26.

By SeraAngel On 03/30/04  

you gals rock!!!!
i sucked royally at math but now i see the light, geometry is fun if applied to the right subject!

i've been working on this almost everyday for about a week now and I just need to fix this to finish it up.

thanks again!

gromcocontact infofreelance bbs