Some aerobatic teams call it Delta some others Wedge. These are my ideas, what you think?
I think Wedge is more appropriate for this formation, from english dictionary: "Wedge: a triangular-shaped piece, especially of food:
Auntie Ann put a huge wedge of fruit cake on my plate.
a wedge of cheese" When you draw a "wedge" of fruit cake, the point is pointing forward (as direction of flight, same for the wedge of fruit cake when flying to my mouth!)
From english dictionary DELTA: an area of low flat land, sometimes shaped approximately like a triangle, where a river divides into several smaller rivers before flowing into the sea. If we follow the flow of the water, we see the point of triangle in opposite direction of water. That's why I don't like to call these formation "Wedge".
Here, some more formations as we like to perform it, I hope these are usefull.