 So you just want to slice, not a problem. Slice mesh allows you to left click and slice from one face to another. Every time you click, it's going to connect the new face to the last face. If you need a specific angle, you can hold down drag, and if you ever need to reset your starting point, just press the spacebar. As you can tell, it normally defaults to crease in the slice, but if you don't want to crease, just set it to uncreased here. Hope that helps, and as always, hope you have a fantastic day, and I'll see you around.