>>84737
Because the triangles are similar.
>>84741
Yeah but why?
>>84753
how old are you
>>84755
16
(USER WAS BANNED FOR THIS POST)
>>84758
http://www.4chan.org/rules
Read the 2nd global rule.
>>84760
Oh sorry typo I'm 18
>>84763
Of course you aren't. Triangle similarity isn't taught that late.
>>84737
x+y+α = 180 degrees
op, review the triangle theorems you have in your textbook and memorize them
>mods don't even ban this underage shit
>>84763
Here, because I feel bad for you. This is basic shit senpai, get it together.
>>84758
>>(USER WAS BANNED FOR THIS POST)
Glorious
>>84758
HOLY SHIT! FUCK YEEEES!!!
THANKS BASED MODS!
>>84758
MODS=GODS
Praise Jesus.
>>84758
rekt
>/thread
>>84758
based mods
>>84773
No, that's begging the question.
You only know the other angle is y because you're told the first angle is a.
If there were right-angle marks anywhere then you'd be right, but there aren't so you're not.
>>84758
BLOWEN THE FUCK OUT