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All measurements in cm.

if you were given the first measurement, eg 15 cm, how would you express a formula to calculate the rest.

Yes I know if I did not round it all to 2 decimal place it would not work. The point is I don't need .o1 of a cm accuracy to build this in the real world. Can this sort of 'error' be built into a math formula?

This is the drawing for half of a window frame to be welded up.

I have to admit I'm not sure the real world application would stand up to a detailed formula.

The idea was to be able to work out the total design with nothing more than one measurement and a formula.However I was more interested in how such a formula would be expressed rather than if it would work. I could only get it to work by rounding everything to 2 decimal places.I'm not even sure if it would work at larger scale.

using what you put above, the closest I can get right now is (using a,b,and c )

c[n]=c[n-a+b]

but that only looks to be part of it.

bobbym wrote:

If A + B = C

what about D, is it B + C?

A quick look around suggests I need to be looking into recursive,would that be right? thanks for your help, much appreciated

" If the next A or B is the previous C, then the next C is the previous A+B"

is probably not very accurate. I guess I'm trying to find out how this would be wrote as a formula that describes how the value of A,B and C change. I know its probably childishly simple to most of you. I would be eternally grateful if someone would point me in the right direction and I'll try and learn more.

yes, sorry, my mistake.

**bill.stead**- Replies: 21

Hi everyone. As i said in my intro I am a welder. I've been asked to construct a spiral made up of triangles. Like most jobs I have sat down to draw it out and make cutting lists etc so I can give the customer a fair estimate of cost.

After doing the old A2+B2=C2 a few times to work out the lengths of the sides I notices I no longer need to do that. The answer for the next triangle is always in the previous one.

E.G If the next A or B is the previous c, then the next c is the previous a+b.(to my level of accuracy anyway lol)

This got me thinking,how would I describe this change of value in math 'talk'.

I'm more interested in the way it would be described than the lvl of accuracy.

I know this is probably a simple question and apologies if I offend anyone.

Thank you all in advance for your patience.

**bill.stead**- Replies: 4

Hi,I'm a welder by trade and I rather like maths. It distracts me way to much. I don't have a high level of education so I hope no one minds me joining the forum. I have a problem (probably quite simple)that has been bugging me of late. I will post it in the help section. Please be kind with me as I know its a simple question. Thank you all in advance.

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