Question

What belongs in the box marked with the question mark in the proof below?
http://i601.photobucket.com/albums/tt92/vctr5/Capturadepantalla2012-08-02alas65104PM.png

Answer 1

what do you think is the reason?

Answer 2

i don't know, i don't get the question :(

Answer 3

they are asking you on what basis m<1+m<2+90degree =180degree ?

Answer 4

@jorgesnz ?

Answer 5

don't get it :S

Answer 6

You are using the substitution law next because you replace m<3 with 90 degrees

Answer 7

does that make sense?

Answer 8

see all angles on a straight line are equal to 180 degree , therefore m<1+m<2+m<3=180 because the all lie in a straight line
does this makes sense?

Answer 9

yeah, thanks

Answer 10

i am happy you got it :)