Help please, I have no idea how to do this and I have a test on it tmrw!

Answer:
Step-by-step explanation:
Supplementary means that 2 angles add up to 180 degrees.
If ACB and ACD are supplementary then they have to add up to 180 degrees.
We know that ACD is smaller than ACB and EGF is supplementary to the smaller of the two.
So then these two are supplementary.
If these are supplementary then the only reason i can think of is that they are supplementary or not. I recently had a test on this too and i may have failed. I have given you all the information i know. Sorry. If it is multiple choce then pick a random one. You may get it correct.
Answer:
See below.
Step-by-step explanation:
We didn't do column proofs when I attended school (in the UK) so I can only show you how we would prove it in the UK.
The angles are supplementary (given).
so < ACB + < ACD = 180
< EGF + < ACD = 180
Subtracting:
< ACB - <EGF = 0
Therefore < ACB ≅ <EGF.
I hope this helps.