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Crafty Maths question

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IsolaPribby · 15/06/2021 15:51

So this is for all you maths geeks out there (and I know there are plenty 😉)

I am crocheting a triangular shawl, I started in the middle, so each row makes it longer and deeper. I have nearly finished one ball of yarn, and want to figure out how big it will be once I finish all three of the balls.
I am sure that there must be a formula to work it out. I can see that each ball of yarn will give the same area, but each subsequent area will be longer and thinner.
I'm looking for an answer in rows, so that if the first ball takes 100 rows, the next will be 40, or 35, or whatever.
Can someone help me? I have attached a photo to help.

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StevenTechMumsnet · 15/06/2021 16:00

I think the ratio of area of similar triangles is the ratio of square of their sides. You are creating a similar, bigger triangle with three balls of wool so the area will be 3 times so the sides should then end up √3 times the size you have now (or about 1.73 times.) How that equates to rows. Hmm. Might have to get some graph paper out. I might also be talking garbage on account of how I left school over 30 years ago. Hmm. Intriguing. Do we have any maths whizzes in the area?

MNHQ

StevenTechMumsnet · 15/06/2021 16:11

I think so. Because the "height" of the triangle is proportional to the sides so it should also go up to about 1.73 times it's original size. And the height is the number of rows. I think (scratches head.)

MNHQ

StevenTechMumsnet · 15/06/2021 16:11

Its not it's. Tsk.

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