transform degenereted block
 

Hello Together,
I am trying to improve a trapeze block into more block with better geometric angle.
I need your help because I want to transform a degenerated block (5 edges) into a block with 4 edges. (On the picture in the red circle). I think that I can use the face marge function but this function doesn't work for my problem.
If you have an idee, can you help me please.
Thanks a lot
Best regards