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#1 2017-01-23 07:18:51

Chelsianna
Guest

Nets of Cubes

I am struggling with finding which net is the correct net for a cube or cuboid. Does anyone know any easier ways to find the correct net? Answer ASAP , needed for an exam.

#2 2017-01-23 07:35:10

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Nets of Cubes

Hi;

There are 11 nets for a cube. Which do you want?


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#3 2017-01-23 20:06:40

Bob
Administrator
Registered: 2010-06-20
Posts: 10,058

Re: Nets of Cubes

hi Chelsianna

Welcome to the forum.

Here's one net of a cuboid.

T1zGhry.gif

For my example I chose a cuboid 4 by 3 by 2.

You need six rectangles, two are 4 by 3 and they will become the top and bottom of the solid.  Two are 4 by 2.  They will form the back and front faces.  The final two are 3 by 2. They will make the left and right faces.

There are a number of ways that those six rectangles could be joined, and still you'd get a cuboid.  For example you could leave out face B from the right hand end and have a new B on top of E.  That would still work.

But it wouldn't work if you joined A to B directly because there has always got to be a side face between the top and the bottom.

A good way of practising this would be to get some paper with squares and try cutting out different possible nets to see how many ways you an find that work.

A cube is just a cuboid with all sides the same length, which makes it simpler.  You'd need 6 squares that fold up to make a cube.  There are a number of ways to join them, to make this work.  If bobbym says there are 11 ways I'm sure he is correct.  I haven't tried to find them myself.  And I don't think you would be asked this in an exam because it's too open ended for a test against the clock.

But I have seen GCSE papers where three different configurations are given and you're asked to say which will work and which not.  For example if you put all six squares in a line, then this would fold up so some faces came on top of others and some faces would be left out.

You might be given a partly completed net and asked to complete it.  Trying some nets and cutting them out is a good way to get better at this.

What exam is it?  It sounds a bit like GCSE (UK) but maybe it isn't.  If you post back I'll look up and see what the syllabus says and if there are any practice questions.

Hope that helps,

Bob


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

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