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

[@hershelkatz6189]

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]

You're in college now?

[@78anurag]

@WahWah02 I dunno I just wanted to k ow

[@Nemoguzapomnit]

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

[@ultrio325]

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

[@arvindagrawal979]

Thank you very much.

[@onesandzeroes]

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]

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.

[@angeloyuanfukuyama6101]

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

[@nandkishorsen6837]

Hi

[@sciencenerd7639]

thank you Sal!

[@TheLivingLegend89]

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]

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?

[@renu0091]

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

[@GoumenPouSawKwè2008]

Well done

[@CorollaChronicles]

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

[@mannymann8814]

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

[@OllieParkerTheGreatOcelot]

That acronym though 💀

[@lukeerikblue958]

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]

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

[@ThomasGiles]

Ahhhhhhhhh..... I see!

[@Schlynn]

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

[@jazerazo]

Oh fuck, I was wrong. Thanks Sal!

[@anniegao9105]

We haven't learn this yet.

[@nandkishorsen6837]

Hi

[@gangstersocks]

Bro I’m gonna fail geometry 💀

[@jdlenl]

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

[@sparky213thousand]

I thought this was going to be a proper proof

[@yaycookies14]

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

[@applepie3683]

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

[@lukaspruess7125]

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

[@applepie3683]

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]

@@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.

[@anniegao9105]

I will trust you this one, okay?

[@troooooper100]

Lol

[@abstrakt5336]

(G)old

[@CollegeBoardSucks]

@pureowner138 lol but also don't forget AAA

[@Yoshikage8008]

I hate math

[@alihesham8167]

Then why are u watchin thid

[@YT_Admin_]

You aren't a human ig