I understand the principal of the Cis-Trans naming system (at least I think so), until I saw this example in my learning material. My teacher doesn't know either so I thought I would post it here.
This is the molecule:
There are two ethyl groups both on the bottom side of the double bond, so it could be cis right?
Apparently not, the book says this is the answer:
Could someone please explain the reasoning behind this? This particular example is unusual because there are three ethyl groups attached to the double bond so I cannot determine which one should be the parent chain. The book doesn't explain.