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To the center of the earth!📉

⁨558⁊ ⁨likes⁊

Submitted ⁨⁨6⁊ ⁨months⁊ ago⁊ by ⁨NONE_dc@lemmy.world⁊ to ⁨[deleted]⁊

https://lemmy.world/pictrs/image/f418776a-2517-4e60-a68f-9bc4bc11bb74.png

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Comments

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  • bjoern_tantau@swg-empire.de ⁨6⁊ ⁨months⁊ ago

    135° for anyone wondering.

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    • expatriado@lemmy.world ⁨6⁊ ⁨months⁊ ago

      correct, just commening the 100/80 intersection looks like 90/90, i think it was intentionally misleading, classic trying to get you problem

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      • Worx@lemmynsfw.com ⁨6⁊ ⁨months⁊ ago

        What a bunch of bullshit. Just draw it way off 90 if you don’t want people to use a protractor. I calculated 125° because of this (but I’m happy I still got the right wrong answer, if that makes sense)

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      • SendMePhotos@lemmy.world ⁨6⁊ ⁨months⁊ ago

        Yes I originally thought 90 but then noticed the absence of a right angle sign. Also 60+40=100 which means the last angle should be 80. Making that perpendicular 100/80

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    • AcesFullOfKings@feddit.uk ⁨6⁊ ⁨months⁊ ago
      [deleted]
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      • Enkers@sh.itjust.works ⁨6⁊ ⁨months⁊ ago

        I’d get out my red pen and write: “Bad diagram. -1pt See me after class.”

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    • slaacaa@lemmy.world ⁨6⁊ ⁨months⁊ ago

      Yes, simple doodle below for anyone wondering. You start from left, and calculate them 1 by 1, based on the angles that you already know. It is quite simple actually, you just have to know they always add up to 180 (within triangle, and when you “split” the space over a straight line).

      Image

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      • stebo02@lemmy.dbzer0.com ⁨6⁊ ⁨months⁊ ago

        you mean to say the right angles aren’t right angles? disgusting, get this outta my sight

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    • Maalus@lemmy.world ⁨6⁊ ⁨months⁊ ago

      Nope. The value is “undefined”. You don’t have enough info to arrive at 135 - you are assuming that the bottom angle (sum of the angles that touch) is 180 degrees. Since there isn’t a datum saying the bottom “line” is straight, nor does it say the triangle on the right is an isosceles triangle, it is impossible to solve.

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      • gedaliyah@lemmy.world ⁨6⁊ ⁨months⁊ ago

        I don’t see any indication that this is limited to the Euclidean plane either

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      • bjoern_tantau@swg-empire.de ⁨6⁊ ⁨months⁊ ago

        Image

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      • Enkers@sh.itjust.works ⁨6⁊ ⁨months⁊ ago

        I think assuming 2 line segments which make up a larger straight line segment to be parallel is generally accepted practice, and that would trump the angles that are drawn inaccurately.

        Of course, it’d be better to put a hash through them both to indicate they’re parallel, especially given the deceptively drawn most-likely-not-a-right-angle.

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    • lugal@sopuli.xyz ⁨6⁊ ⁨months⁊ ago

      For context: it used to be 675° a few years back so the math checks out.

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      • expatriado@lemmy.world ⁨6⁊ ⁨months⁊ ago

        that’s not how global warming works

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    • ThisIsAManWhoKnowsHowToGling@lemmy.dbzer0.com ⁨6⁊ ⁨months⁊ ago

      I got 125.

      180-(90-35)=x 180-55=x 125=x

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      • LotrOrc@lemmy.world ⁨6⁊ ⁨months⁊ ago

        How assuming it is a right angle Nothing stays that it is

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      • erin@lemmy.blahaj.zone ⁨6⁊ ⁨months⁊ ago

        It isn’t 90 degrees because the image is misleading. 60+40+y=180. y=80

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  • Coskii@lemmy.blahaj.zone ⁨6⁊ ⁨months⁊ ago

    I hated pictures like this in school. The numbers are just slapped on an inaccurate image and somehow they expect people to ignore the obvious right triangles and just focus on the math part of it.

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    • CaptainBasculin@lemmy.ml ⁨6⁊ ⁨months⁊ ago

      Fun fact: In Turkey’s university admittance exam, all angles have to be absolutely accurate, and measurements have to be scaled down perfectly to the visible shape in a geometry question.

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      • Enkers@sh.itjust.works ⁨6⁊ ⁨months⁊ ago

        all angles have to be absolutely accurate

        To what tolerance, though? Writing math exams has now become an engineering problem.

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    • SchmidtGenetics@lemmy.world ⁨6⁊ ⁨months⁊ ago

      If it was to scale you could just use a protractor and skip the whole math part, which is the entire part of the lesson…

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      • Coskii@lemmy.blahaj.zone ⁨6⁊ ⁨months⁊ ago

        I don’t see that as a downside as long as these two questions are also included.

        How many degrees make up the inner angles of a triangle?

        How many degrees make up one side of a straight line?

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      • Pacattack57@lemmy.world ⁨6⁊ ⁨months⁊ ago

        And what’s wrong with that. Utilizing real world solutions to problems is a life skill. Not some obscure formula that you will forget anyway.

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      • elxeno@lemm.ee ⁨6⁊ ⁨months⁊ ago

        Then they could use decimals so it’s unlikely to get it right without calculating, 60.17°, 40.29°, 35.43°

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    • explodicle@sh.itjust.works ⁨6⁊ ⁨months⁊ ago

      If the student eventually does geometry for money, they’ll discover that customer CAD files invariably have some bizarre error like this.

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    • nul9o9@lemmy.world ⁨6⁊ ⁨months⁊ ago

      I was scared I forgot basic trig stuff.

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  • wieson@feddit.org ⁨6⁊ ⁨months⁊ ago

    It’s even easier than going the triangle route.

    A four-corner shape always has 360° internally.

    So the internal angle of corner X is 360-(60+40+35).

    The exterior angle therefore is 360-360-(60+40+35) = 60+40+35 = 135

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    • brown567@sh.itjust.works ⁨6⁊ ⁨months⁊ ago

      That’s based on the assumption that the two angles in the middle add up to 180, which can’t be assumed by inspection alone as demonstrated by the visibly square 80° angle

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      • surewhynotlem@lemmy.world ⁨6⁊ ⁨months⁊ ago

        No, you should completely ignore the bottom half of the center line. You end up with a shape with four turns. Those four internal angles always add to 360.

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    • anonymouse@sh.itjust.works ⁨6⁊ ⁨months⁊ ago

      Nice one, forgot this was an option too. You are missing a set of brackets though ;)

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  • BlueMagma@sh.itjust.works ⁨6⁊ ⁨months⁊ ago

    I love that every comment focus on the math puzzle. Since the other stuff is clearly uninteresting.

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