Abbreviations for similar triangles (1 Viewer)

[YBK]

Hey

I know with congruent triangles you can say, SSS, SAS..

but what about similar triangles, are there any abbreviations?

thanks!

 

[Templar]

Abbreviations for similar triangles is not advised. It's best to write out the entire case.

 

[YBK]

Abbreviations for similar triangles is not advised. It's best to write out the entire case.

arg... crap, that means I have to memorise them for the 2 unit test tomorrow.. !!!

 

[acmilan]

What abbreviations can you use for similar triangles?

 

[pLuvia]

My maths teacher told me that in the HSC we are not allowed to abbreviate words i.e. instead of alt. *angle sign*, we have to write "alternate angles".

Has it always been like this?

 

[acmilan]

You CAN use symbols so long as they are accepted ones. You cant go off and make up your own symbols.

 

[Templar]

There are no universally accepted abbreviation for similiar triangles, so it's up to the marker whether or not to accept your argument.

You can probably get away with alt angle sign. With SAS etc, they are recognised as congruency conditions and hence cannot be used for similar triangles.

 

[Trebla]

Hey

I know with congruent triangles you can say, SSS, SAS..

but what about similar triangles, are there any abbreviations?

thanks!

What I would write as a conclusion in brackets would either be:
- Equiangular
- Two sides in proportion and included angle equal etc

 

[HamuTarou]

yeah...or something similar if u cant remember the whole definition

 

[stargaze]

Is 2 Angles test allowed?

Or do u have to go on to prove the last angles are ' equingular ' ?

 

[LostAuzzie]

Well if two angles are equal the third angle is equal due to angle sum.
So i guess you shouldnt need to but do it anyway, just in case.

 

[KFunk]

I thought that you could say Δ ABC ||| Δ DEF (AAA)

i.e. triangle ABC is similar to triangle DEF because they have three angles equal.

(or Δ ABC ||| Δ DEF (sides in equal ratio) ... once you've proven that that is the case)

 

[YBK]

I thought that you could say Δ ABC ||| Δ DEF (AAA)

i.e. triangle ABC is similar to triangle DEF because they have three angles equal.

(or Δ ABC ||| Δ DEF (sides in equal ratio) ... once you've proven that that is the case)

yeah, that's exactly what I though..
everyone's telling me you can't.

 

[pLuvia]

That is a correct way isn't it. Because you stated the two triangles being similar and stated the test you used to figure it out

 

[acmilan]

Yeah KFunk's notation is fine to use.

 

[word.]

according to cambridge AA suffices, and according to keypad from an old post
set out like so:

from cambridge:

in triangles TCN and RAY
1. angle TCN = angle RAY = 90 degrees (given)
2. angle CNT = angle AYR (given)
so ΔTCN ||| ΔRAY (AA).

also you can use SSS, SAS, RHS if the sides are proportional:
Δ ABC ||| Δ DEF (RHS)
with similarity ratio 3:4

etc.