Both lines move the same way
A rising wedge has a rising floor and a rising ceiling, and the two lines converge. A falling wedge has a falling floor and a falling ceiling, converging. A channel has parallel lines. The mistake we see most often is a rising channel — parallel, healthy enough — renamed as a wedge because the trader is bored or frightened.
Hold a ruler to both boundaries. If you can slide one line onto the other without changing the angle, you have a channel. Say channel. The word wedge is not a prize.
The close back through the line
In class we treat a close back through the lower line of a rising wedge as the moment the sketch changes status. Until that close, it is a wedge in progress, which means it might simply be a climb. We write in progress on the sheet so the name cannot harden overnight.
Evening five of the circle is wedges and channels side by side, on purpose. If you only remember one habit, remember the parallel test. It will save you from a mood dressed up as geometry.