Is there a name for when someone thinks they are really bad at something (for example math) and they have learned not to trust their own intuition at all so they make really wild errors by second guessing themselves?
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@futurebird i was a kid like that, and i later got diagnosed with dyscalculia. The reason i didnt get diagnosed as a kid, was because i have very strong memory so i just memorized everything. So i could really struggle if a triangle was a little rotated, because it didnt fit the example i memorized.
This is interesting. The student happens to be really good at memorizing things. And thinking back when a problem is rotated it really throws her.
Maybe we can work on doing things like first rotating the paper to a familiar position.
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@Bumblefish @3TomatoesShort @EverydayMoggie
"The whole thing where you use them to make angles is deep magic that only wizards can perform."
I've noticed that the angle construction is harder for students. Not just this one who's having extra difficulty, but all of them are a little mystified when I say "now we'll copy an angle" but there is some good intuitive geometry in this construction.
A compass isn't just for making circles. It's a fixed distance you can put wherever you want.

@futurebird @3TomatoesShort @EverydayMoggie
intuitive…you keep using that word. I do not think it means what you think it means (to paraphrase the immortal Inigo Montoya
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@futurebird oh, no. This isn't obvious at all.
If anyone has ideas to make the idea of copying an angle more obvious I would love it.
I've tried pointing out that it's basically copying a triangle too. You are duplicating the length of all three sides and thus you get the angle for free.
It's "Side Angle Side" ... but that seems maybe more confusing than just doing it a few times and feeling how well it works.
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@futurebird @3TomatoesShort @EverydayMoggie
intuitive…you keep using that word. I do not think it means what you think it means (to paraphrase the immortal Inigo Montoya
)@Bumblefish @3TomatoesShort @EverydayMoggie
OK let me try this one:
How would you use a compass to make a very pointy isosceles triangle like a wizard's hat? For a quilt or something.
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@Bumblefish @3TomatoesShort @EverydayMoggie
OK let me try this one:
How would you use a compass to make a very pointy isosceles triangle like a wizard's hat? For a quilt or something.
@futurebird @3TomatoesShort @EverydayMoggie I wouldn’t. I’d use two rulers as god intended.
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@futurebird @3TomatoesShort @EverydayMoggie I wouldn’t. I’d use two rulers as god intended.
@Bumblefish @3TomatoesShort @EverydayMoggie
Ok but try.
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@Bumblefish @3TomatoesShort @EverydayMoggie
Ok but try.
@futurebird @3TomatoesShort @EverydayMoggie I got a circle.
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@futurebird @3TomatoesShort @EverydayMoggie I got a circle.
@Bumblefish @3TomatoesShort @EverydayMoggie
Great use the center and the circle to make a pointy triangle.
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@futurebird @3TomatoesShort @EverydayMoggie I got a circle.
@futurebird @3TomatoesShort @EverydayMoggie Oh wait if I lie it down and trace around it I got a…wait wait *that’s* got an angle . What’s going on here?
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@Bumblefish @3TomatoesShort @EverydayMoggie
Great use the center and the circle to make a pointy triangle.
@futurebird @3TomatoesShort @EverydayMoggie Ok so where I’m holding the compass is a pointy triangle.
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@futurebird @3TomatoesShort @EverydayMoggie Oh wait if I lie it down and trace around it I got a…wait wait *that’s* got an angle . What’s going on here?
@Bumblefish @3TomatoesShort @EverydayMoggie
OK now I'm confused what you have done. This is what I was expecting. But, people always surprise me.
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@Bumblefish @3TomatoesShort @EverydayMoggie
OK now I'm confused what you have done. This is what I was expecting. But, people always surprise me.
@futurebird @3TomatoesShort @EverydayMoggie No that would not occur to me in a million years.
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@futurebird @3TomatoesShort @EverydayMoggie Ok so where I’m holding the compass is a pointy triangle.
@Bumblefish @3TomatoesShort @EverydayMoggie
EXACTLY!
The legs of the compass are the same length (roughly) so it makes an isosceles triangle.
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@futurebird @3TomatoesShort @EverydayMoggie No that would not occur to me in a million years.
@futurebird @3TomatoesShort @EverydayMoggie However if you had asked me to cut it like a pizza we’d have been fine.
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@3TomatoesShort @EverydayMoggie @futurebird I was going to suggest paper modeling. I can’t calculate anything to save my life, but give me a concrete thing I can shape with my hands and things start to make sense. You mentioned compasses. Nobody has reliably convinced me they can do anything except make circles. The whole thing where you use them to make angles is deep magic that only wizards can perform.
@Bumblefish @3TomatoesShort @EverydayMoggie @futurebird
Using a compass to draw an isosceles triangle is a step too far for me.
I’d start with physical paper, then model different scales in a digital tool and then translate that to angle degrees + line proportions.
I’ve repeated this process enough that I can “tear” a flattened 3-D cube out of a sheet of paper in capital T or lower-case t configurations. -
@futurebird @3TomatoesShort @EverydayMoggie However if you had asked me to cut it like a pizza we’d have been fine.
@Bumblefish @3TomatoesShort @EverydayMoggie
OK pizza good to know.
Anyway. Connecting the center of a circle to two points like that is a great way to create an angle. When you copy an angle you are just cutting two pizza slices that are the same.
If the pizzas are the same size, and the distance between the points on the circle is the same. The angle at the top (center) is the same.
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@Bumblefish @3TomatoesShort @EverydayMoggie @futurebird
Using a compass to draw an isosceles triangle is a step too far for me.
I’d start with physical paper, then model different scales in a digital tool and then translate that to angle degrees + line proportions.
I’ve repeated this process enough that I can “tear” a flattened 3-D cube out of a sheet of paper in capital T or lower-case t configurations.@dahukanna @Bumblefish @3TomatoesShort @EverydayMoggie
That sounds like so much work to me.
If you want someone with two parts that are the same length that start at the same point they have to be on a circle. No need to measure anything.
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I'm trying to understand this.
If I flip a board "l-r" will the result be different than "r-l" ?
The way I'm picturing this the answer would be "no" right?
@futurebird
Yeah l-r or r-l is the same but many kids would flip top-bottom or rotate. -
@futurebird
Yeah l-r or r-l is the same but many kids would flip top-bottom or rotate.I think focusing on the results might help? If they go top/bottom the text will be upside down.
So "flip it so the edge with the text is *still* near you but the lighter side of the board is on top" maybe?
The "left right" makes me think of rotating since with 90 degree turns left and right matter?
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@dahukanna @Bumblefish @3TomatoesShort @EverydayMoggie
That sounds like so much work to me.
If you want someone with two parts that are the same length that start at the same point they have to be on a circle. No need to measure anything.
@futurebird I‘ve no cognitive intuition for geometry, never been able to tell left from right, am a visual learner & can imagine an Apple+smell it+hear crunch when I bite into it, …
So validating a flat planer isosceles triangle needs deliberate cognitive effort, else i’m guessing based on “way wind blows” or my mood.As a digital Designer, developed systems that enable expressing visual scene by literally, mentally mathematically raytracing scene. POV ray was “heaven”- camera, lights, action!