Question

how can i prove these?

Answer 1

q' 10right at the top

Answer 2

so those ppl dnt know the altenate xD
poor lolz
it like prove the alternate thm

Answer 3

maybe he/she is still in school

Answer 4

everything here is a postulate, and not a theorem

Answer 5

@aajugdar its not for school , if it was scholl then its enough to say alternate :P

Answer 6

anyway @rani
u have the steps just write the postulates that justify them

Answer 7

Try below :

(i) - Same side interior angles theorem*
(ii) - linear pair angles addup to 180
(iii) - By substitution
(iv) - By subtraction property of equality

Answer 8

* we call it theorem even though it is not

Answer 9

this thing is freaks me out xD
the alternate thm prove all of the above so why i use all of them to prove it xD

Answer 10

yes you need to call one of them a `postulate`, then u can use it to prove everything else....

Answer 11

without alternate i wont have Same side interior angles

Answer 12

it doesnt matter which one u call a `postulate`

Answer 13

which make no sense to me

Answer 14

guys can one someone just explain it to me, I'm studying for my exam... I'm in hurry
if u guys don't mind..

Answer 15

You can take any one of below result as `postulate` and prove the remaining stuff :
1) corresponding angles are equal
2) alternate interior angles are equal
3) alternate exterior angles are equal
4) same side interior angles are supplementary
...

Answer 16

u can use the parallel axiom as a postulate but the interior thingy xD
what im saying ... @ganeshie8 is that there is many proofs u can start with
but that book thing why they teach wrong steps :O

Answer 17

Alright! so from beginning how can i respond to this question or any of these ?

Answer 18

\[\tan i= \frac{ AC }{ AB }=\frac{ BD }{ DC }=\tan i'\]donc\[i=i'\]or \[a=i+\pi/2=i'+\pi/2=a'\]