Geometry Help! please?! provide the reasons for the proof: Given: m<1 = m<2 prove: AC is perpendicular to BD?

[juanito]

I am so confused on proofs! This is what i have so far: ( I would appreciate if you could tell me if it is wrong or right!) a. m<1 = m<2 : given
b. <1 is supplementary to <2. : Definition of supplementary angle
c. m<1 + m<2 = 180degrees :Linear pair postulate
d. m<1 + m<1 = 180degrees
2(m<1) = 180degrees : (this is one step. but the 2(m<1) = 180degrees is right below the first one.) Substitution property of equality
e. m<1 = 90degrees : Substitution property of equality
f. <1 is a right angle. : idk this one.. help please!
g. AC is perpendicular to BD : idk this one either.
Which ones are wrong? and which ones are right? any help is appreciated! Thank you!!

[josephus]

Assuming you are given a picture of intersecting lines.

Switch the reasons for b) and c)
b) the angles form a linear pair , from the picture, so this is linear pair postulate
C) Then the measures add to 180, because they are supplementary. Defn of supplementary.
E) you have divided both sides of the equation by 2; or multiplied by 1/2; multiplication property of equality
F) definition of right angle
G) definition of perpendicular

Hoping this helps!