What is the missing step in the given proof?

Statement: m 4 = m 15
Reason: Substitution Property of Equality

Statement: m 4 + m 8 = 180°
Reason: definition of supplementary angles

Statement: 7 and 8 are supplementary.
Reason: Linear Pair Theorem

Statement: m 4 = m 16
Reason: Transitive Property of Equality

Statement: 15 and 8 are supplementary.
Reason: Transitive Property of Equality

Question

What is the missing step in the given proof?

Statement: m  4 = m  15
Reason: Substitution Property of Equality

Statement: m  4 + m  8 = 180°
Reason: definition of supplementary angles

Statement:   7 and   8 are supplementary.
Reason: Linear Pair Theorem

Statement: m  4 = m  16
Reason: Transitive Property of Equality

Statement:   15 and   8 are supplementary.
Reason: Transitive Property of Equality

anonymous · Answer

attachment

anonymous · Answer

there is the picture

haleyelizabeth2017 · Answer

Here, this might be easier so people don't have to go back and forth between word and this :)

anonymous · Answer

@haleyelizabeth2017 do you know what the answer could be?

haleyelizabeth2017 · Answer

I actually was looking at it, and I do not.....I haven't done this stuff for a while and I have never seen a proof like that :'(

anonymous · Answer

well thanks for trying :)