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#1 2008-03-04 17:00:43
- Roxane
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- Registered: 2008-03-04
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um hi i need help on something...
how do you find 15 cm with just a piece of paper (21.5 cm by 28 cm). No rulers allowed
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#2 2008-03-04 17:12:38
- Roxane
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- Registered: 2008-03-04
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Re: um hi i need help on something...
plz help!!!
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#3 2008-03-04 18:44:36
- Identity
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- Registered: 2007-04-18
- Posts: 934
Re: um hi i need help on something...
I don't know how exactly, but a very good approximation is to fold the length of the paper in half twice, and the width in half once.
Then 15cm is the length of the diagonal (approx)
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#4 2008-03-05 04:03:17
- mathsyperson
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- Registered: 2005-06-22
- Posts: 4,900
Re: um hi i need help on something...
No rulers allowed
Use measuring tape then. 
Why did the vector cross the road?
It wanted to be normal.
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#5 2008-03-05 05:12:01
- JaneFairfax
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- Registered: 2007-02-23
- Posts: 6,868
Re: um hi i need help on something...
You should be able to get 7cm, 14cm and 21cm from the side of length 28cm. From 21cm and the other side, of length 21.5cm, you should be able to get 0.5cm. Double that portion to 1cm, and then add it to 14cm.
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#6 2008-11-01 15:38:20
- musician_14
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- Registered: 2008-11-01
- Posts: 4
Re: um hi i need help on something...
That is to much work.......this is how you do it.
Using the 21.5 cm side, fold it diagonally so that the side lines up with the side that is 28cm. This will leave you with 6.5cm to complete the full length.
Now using this length 6.5cm, line it up to the width 21.5cm, and you will be left with 15cm exactly to complete the width.
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