More on why SSA is not a postulate | Congruence | Geometry | Khan Academy

Поделиться
HTML-код
  • Опубликовано: 13 дек 2024

Комментарии • 41

  • @hershelkatz6189
    @hershelkatz6189 7 лет назад +33

    I'm in a geometry class, and the teacher put a problem of proving 2 triangles congruent on the board to prove. So one guy got up, and started writing down theorems and reasons, until he got to it having 2 sides and an angle the same. He then said "they're congruent because of ASS, angle, side, side", and wrote each letter as he said it. Smiling, he turned to the teacher, me, and the rest of the class, and was like "it works!" The rest of the class and I started giggling, and then we burst out laughing for a few minutes. The teacher gave a weird and surprised look at my friend who wrote it, walked over to the board, erased all of his work, and was like "we don't use that word!"
    This is a 9th grade class.

    • @78anurag
      @78anurag 3 года назад +1

      You're in college now?

    • @78anurag
      @78anurag Год назад

      @WahWah02 I dunno I just wanted to k ow

  • @Nemoguzapomnit
    @Nemoguzapomnit 6 лет назад +13

    I can't help but giggling after Sal notice that stuff about this funny acronyme. Probably If he wouldn't notice that I wouldn't even detect it

  • @arvindagrawal979
    @arvindagrawal979 4 года назад +2

    Thank you very much.

  • @ultrio325
    @ultrio325 3 года назад +4

    "We don't want people giggling in math"
    Me, an intellectual: 360°=351°+9°=420°-69°+9°

  • @onesandzeroes
    @onesandzeroes 11 лет назад +2

    Thanks for the video, before it I couldn't understand why on earth SSA is not a postulate, now I've seen the light :-)

  • @DehXable
    @DehXable 13 лет назад +1

    You should include "Ambiguous Case" in the description. This would have been helpful when I was learning that. Or, you could make another video and relate this to the Ambiguous Case of the Law of Sines.

  • @renu0091
    @renu0091 11 лет назад +2

    Well... the RSH theorem is applicable for congruency too, along with SSS, ASA, SAS and AAS...

  • @sciencenerd7639
    @sciencenerd7639 2 года назад

    thank you Sal!

  • @TheLivingLegend89
    @TheLivingLegend89 12 лет назад +2

    That is not necessarily true, there is an SsA congruence theorem for triangles, where the given side S opposite of given angle A is the larger of the two given sides. These conditions will guarantee congruence, the HL postulate itself is a special case of the SsA congruence theorem.

    • @helphowdoinputusername3571
      @helphowdoinputusername3571 Год назад

      He literally explained that. That's what the entire video was explaining. Were you even paying attention to the video you're trying to correct?

  • @GoumenPouSawKwè2008
    @GoumenPouSawKwè2008 6 лет назад

    Well done

  • @angeloyuanfukuyama6101
    @angeloyuanfukuyama6101 4 года назад +1

    This channel is on my school's bulletin board you're getting popularity sir

  • @CorollaChronicles
    @CorollaChronicles 3 года назад +1

    HA my 7th grade Pre-Algebra teacher once wrote an abbreviation for associative property. Guess what she abbreviated it as at first.....

  • @mannymann8814
    @mannymann8814 2 года назад

    Is there a Theorem that says if and obtuse angle and two other sides are congruent then the whole triangle is congruent?

  • @OllieParkerTheGreatOcelot
    @OllieParkerTheGreatOcelot 3 месяца назад

    That acronym though 💀

  • @lukeerikblue958
    @lukeerikblue958 3 года назад

    Isn't it always the case that if the first 'S' is the longest side, then SSA can prove congruence regardless of whether or not the 'A' is obtuse? I mean that still includes an extra piece of information by specifying which S is allowed.

    • @akhipazham7270
      @akhipazham7270 Год назад

      Even if S was the longest, it would still have 2 ways of being constructed if the angle is acute

  • @Schlynn
    @Schlynn 13 лет назад

    You could just explain it as a problem that you get when you take the arcsin of some values.

  • @jazerazo
    @jazerazo 13 лет назад +1

    Oh fuck, I was wrong. Thanks Sal!

  • @anniegao9105
    @anniegao9105 12 лет назад

    We haven't learn this yet.

  • @ThomasGiles
    @ThomasGiles 11 лет назад +2

    Ahhhhhhhhh..... I see!

  • @yaycookies14
    @yaycookies14 13 лет назад

    SSS Postulate, ASA Postulate, SAS Postulate, AAS Theorem, is everything I was taught, any other ones are untrue.

    • @applepie3683
      @applepie3683 7 лет назад

      What about 2 sides and an angle in front of the big side?

    • @lukaspruess7125
      @lukaspruess7125 3 года назад

      @@applepie3683 I'm not quite sure what case your describing, but I believe that would just be SAS...

    • @applepie3683
      @applepie3683 3 года назад

      No, SAS is when the angle is between the 2 equal sides. However if you have 2 sides equal and an angle that isn't between the 2 sides it is not guranteed the 2 triangles are congruent, SSA says that they are congruent under the premise the angle lies opposite to the bigger side in both triangles.

    • @lukaspruess7125
      @lukaspruess7125 3 года назад

      @@applepie3683 Very intresting, Thank you! I just tested it right now and It seems the premise you have outlined is much more accurate than the 'obtuse vs acute' premise in the video.

  • @jdlenl
    @jdlenl 13 лет назад +1

    So, according to you, Sal, 'ambiguous' is spelled...
    'ambιġuous'?
    You dotted the G not the I. :3

  • @gangstersocks
    @gangstersocks 3 года назад

    Bro I’m gonna fail geometry 💀

  • @sparky213thousand
    @sparky213thousand 9 лет назад

    I thought this was going to be a proper proof

  • @CollegeBoardSucks
    @CollegeBoardSucks 13 лет назад

    @pureowner138 lol but also don't forget AAA

  • @anniegao9105
    @anniegao9105 12 лет назад

    I will trust you this one, okay?

  • @troooooper100
    @troooooper100 13 лет назад +1

    Lol

  • @Yoshikage8008
    @Yoshikage8008 8 лет назад +3

    I hate math