reasoning: (AAA) or (equilangular) (1 Viewer)

[lillaila]

In proving similar triangles, is the reasoning (AAA) or (equilangular) ? .........my teacher says they wont accept "(AAA), u must write (equilangular)"...............i like writng shorter reasons

 

[Rahul]

i have never been told to write (equilangular)
a proof such as the following has been enough:

"/" = (angle)

/ABC = /DFG....proof, eg: alt angles are equal, etc. (A)
/CAB= /FDG....proof (A)

therefore TRiangle ABC is similar to DFG (AA)

and another thing, u only need to prove two angles, becoz then the third one has to be identical becoz of angle sum of triangles

 

[kini mini]

"Equiangular" is apparently the preferred form, though Grammar taught us that AA was perfectly fine .

 

[Lazarus]

I lost marks in a school test once (which was actually taken from a past HSC paper) because I wrote AAA instead of equiangular.

 

[abdooooo!!!]

i lost marks in a school exam for writing equilangular. i said to my teacher writing (AAA) isn't the approprate way for doing similar triangles she wouldn't listen, and the weird thing is she wouldn't even accept (AA) for an answer, she wants all the angles proved, so you have to write another line of reasoning when you already proved two corresponding angles.

 

[tooheyz]

yeah they're pretty picky with the reasoning and proving these days. yeah i always write both reasons when i get a question like that... better safe than sorry

 

[Minai]

thats weird
I've been taught u cant use that AAA stuff for similiarty, only for congruent triangles, therefore u should use equiangluar..but if ur teachers say otherwise

 

[KeypadSDM]

Originally posted by MinAi
thats weird
I've been taught u cant use that AAA stuff for similiarty, only for congruent triangles, therefore u should use equiangluar..but if ur teachers say otherwise

Trust me you have been mistaught:
Congruence:
SSS
SAS
RHS
AAS

Similarity:
AA
SAS (Common ratio)

and for abdooooo!!!

Your teacher is a bloody idiot, you only need to find 2 angles. If she marks you wrong in that for an HSC assessment because you didn't write the 3rd angle down as equal then complain to the head of mathematics at your school...

 

[Rahul]

Originally posted by KeypadSDM

and for abdooooo!!!

Your teacher is a bloody idiot, you only need to find 2 angles. If she marks you wrong in that for an HSC assessment because you didn't write the 3rd angle down as equal then complain to the head of mathematics at your school...

i think u are a bit confused.....the problem was whether we have to write "equilangular" or simply "AA". not abt a problem if the 3rd angle was not found.

 

[KeypadSDM]

Originally posted by abdooooo!!!
and the weird thing is she wouldn't even accept (AA) for an answer, she wants all the angles proved, so you have to write another line of reasoning when you already proved two corresponding angles.

I was commenting on this line...

 

[Rahul]

fair enuff.

 

[Minai]

Originally posted by KeypadSDM


Similarity:
AA
SAS (Common ratio)

Mayb u have been mistaught
in all textbooks ive used, there are no 'tests' for similarity, u cannot use AA or SAS or watever as a proof for similar triangles - u must state that either corresponding angles are equal (equiangular)
SAS is completely wrong, because sides are in proportion, not equal, in similar triangles