Do Languishites know the Geodreieck?

[Syt]

This came up on Reddit, where some people claim that this device, used primarily in geometry classes in school, is not known outside German speaking countries, whereas others say that's nonsense.

I could Google, but I thought I'd rather ask the Languish hive mind.

Did you have something like this in school? It's 15 cm wide and generally used for drawing/measuring angles, drawing parallel lines, etc., and at least in my time was a key item:



There's larger versions of it, including for use on the black board:



Did you use something like that? Or something else?

[Eddie Teach]

We just use the curved part and call it a protractor.

[celedhring]

Yes, that's a "escuadra de geometría" over here. Protractors were far more common though, usually only the showoff kids had the full thing.

[HVC]

We used a protractor in ontario. So, i guess only the curved one in the middle of your image. Didn't use one with a outer triangle.

[Richard Hakluyt]

Only saw one of those a couple of times; usually we used a protractor and two set squares (triangles) one with 45/45/90 angles and the other with 30/60/90 angles.

[Duque de Bragança]

Triangle or équerre géométrique. Have not used or even seen one since primary school (online sighting post Syt's query does not count  ).

Esquadro geométrico in Portuguese.

Basic équerre/esquadro version is much more common, and bigger versions are used in DiY and by handymen.

[Syt]

We just use the curved part and call it a protractor.

Tbf, I'm not sure what the reason for the triangle shape is, or what benefit it gives.

[The Brain]

I don't think it was completely unknown, but standard was just a protractor.

[Josquius]

The small one looks vaguely familiar from when I was in school.
The giant one instantly rings bells of Japanese schools with me

[DGuller]

What's the advantage of the triangle thing over just the semi-circle thing?

[Richard Hakluyt]

What's the advantage of the triangle thing over just the semi-circle thing?

Much more effective in combat situations.

[Jacob]

We just use the curved part and call it a protractor.

Tbf, I'm not sure what the reason for the triangle shape is, or what benefit it gives.

The triangle is for drawing 90° and 45° angles.

Typically, we used separate set-squares and protractors like this:



I used them in elementary school for various geometry things, and a fair bit in engineering drafting class in Uni (though the triangles were significantly larger).

[HVC]

also, when i first read the title i thought you had joined a MLM haha

[Sheilbh]

Yeah, same as Jake. Never seen the combo though.

[DGuller]

When I was little, I saw that my grandmother had a retractable straight edge back from her school days.  I didn't understand the point of it, what utility does the retractable part give to it?  It's not like you can make the straight edge more compact, the retractable part of it doesn't line up with the outside shell.  Years later, when I was taking a history of math class, I realized that it was a slide rule.