Hello everyone in internet maths land. This is where I would live every day if I could.

I'm Zoe, I'm 30 and live in Totnes, Devon, UK (I remember having to repeat that line in French all the time in school. I think it's one of the first things they teach you).
Maths was my favourite subject at school and even now when I'm blue I try maths tests online. Due to health and disability problems my dream of teaching maths to anyone that would listen stopped after leaving school. Now I am in constant pain and extreme fatigue due to Fibromyalgia and Costochondritis. It's taken me 20 minutes just to type to here. Fun doesn't even come close. My sister who is also disabled (for other reasons) hates maths and leaves everything to me to calculate (sometimes I just pass one to her instead ).
Anyway, the reason I joined this forum is my sister has stumped me on a question and I need help from you lovely, clever, good looking, fantastic people (flattery doesn't always work but I thought I'd give it a try ).

The question is to come up with a formula to help make envelopes for greeting cards. When we are both well enough we make greeting cards but some of the designs are made from scratch so don't come with ready made envelopes. This is the problem, we don't know how to make the triangle flapped envelopes that fit well without gaps or too much room. This is where a formula would really come in handy as it would be able to be applied to help make envelopes for LARGE and small cards.

Maximum card size - Length 148 mm x Width 110 mm
Flaps from card area to tip of triangle: Top - 64 mm, Sides each - 70 mm & Bottom 63 mm.

I would have put it into a table or inserted a picture but none of my top buttons work, never mind.

Well there it is, please feel free to message me if you have any questions about this or even anything in general. Think I'm gonna go now and join my snoring Chihuahuas in dream land.

TTFN everyone

Zoe
xoxox
(P.S. Sorry if I've spelt anything wrong or missed a space. I'm blamming my sister as she's not here to defend herself. hehehe )

Hey Zopo82!

You mean like this?

Thank you ILikeSerena,
That's the shape I have but I'm looking for an equation so that I can input any size card and have the right flaps to make an envelope for it. Been looking all over for an answer but haven't found anything yet.
xoxox

Originally Posted by Zopo82
Thank you ILikeSerena,
That's the shape I have but I'm looking for an equation so that I can input any size card and have the right flaps to make an envelope for it. Been looking all over for an answer but haven't found anything yet.
xoxox
Seems to me you should scale the top and bottom flaps with the height, and the side flaps with the width.

In other words, if you have a greeting card with width W and height H, you should make the following envelope.
Flaps from card area to tip of triangle: Top - W x (64/110) mm, Sides each - H x (70/148) mm & Bottom W x (64/110) mm.

Cheers!

Brilliant will give it a go tomorrow and let you know how it goes.
Many thanks
xoxox

Sure! I'll be waiting!

Nice post !

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