lego technic construction triangle?

[Diamabolo]

Hello lego technic constructors..

I thought that fits
can I even build a right angled isosceles triangle?

[62Bricks]

2 hours ago, Diamabolo said:

can I even build a right angled isosceles triangle?
 

Not with sides of whole-stud values, no. The ratio of the sides to the hypotenuse is 1 to the square root of 2. The square root of two is an irrational number, meaning it can't be expressed by dividing two integers.

To create an isosceles right triangle, you will need to find a technique that allows you to adjust the length of the hypotenuse infinitely. I have used a technique like this, sliding two axles back and forth to the length needed.

Edited December 9, 2021 by 62Bricks

[Mylenium]

21 hours ago, Diamabolo said:

can I even build a right angled isosceles triangle?

Pretty much all of LEGOs elements produce 60/ 33/ 18 degree and so on angles when used directly due to their length ratios. as suggested, you will have to create some way of adjustment or fake it. If you're not too strung up on doing this with Technic elements, hinges and ball joints can work great to do some of that stuff. For Technic you can often fake it by inserting extra 2 L elements on one corner to get a fake hinge and offset the beams enough to disguise any inaccuracies.

Mylenium

[Erik Leppen]

As said by @62Bricks, you need a ratio of 1 : 1 : square root of 2, which equals 1.41421356... , a number which cannot be the ratio of two whole numbers. 7 / 5 = 1.4 comes close and 10 / 7 = 1.42857... comes close, so the triangles with sides of lengths (5, 5, 7) or (7, 7, 10) are almost right, but not exact.

So, how exact do you need it to be? In practical usage, I find the (5, 5, 7) triangle - basically the same as the (10, 10, 14) in your photo - to be good enough, even though it's not exact. But I don't build polyhedra ;) Also, if you use gray/tan pins, you can allow some leeway.

Also, the (3, 4, 4) triangle has one angle that is almost 45 degree. Again, not exactly (about 44,05 degrees).

I think it should be mathematically possible to construct an exact 45-degree angle, but probably not in a straightforward way.

[Diamabolo]

On 12/9/2021 at 11:31 AM, Diamabolo said:

Hello lego technic constructors..

I thought that fits
can I even build a right angled isosceles triangle?

many thanks for the help.
I've decided that the 90 degree angle doesn't really matter. I left enough space between the parts so that it still works

https://twitter.com/MartinSchwab9/status/1469421044335357958?s=20

 

[62Bricks]

Hey, that's cool