It would be much easier to implement a master/slave relationship option between wedges and another block and have the game perform some behind-the-scenes visual trickery.
How it would work:
Select the wedge with "C" as the master.
Select another block with "V" as the slave.
When the master wedge is placed, the game automatically draws the master wedge first, with that coordinate getting all the features of that wedge block type. Nothing new here.
Then, after this new master/slave relationship is established ("c", "v"), the game draws a complimentary "phantom wedge" of the same type as the slave block in the remaining space of the master block. When the master wedge is destroyed/removed, automatically remove the "phantom wedge" along with it. No additional HP, no additional bonuses. The "phantom wedge" is just for looks. Bottom line: No new block IDs (unless the slave blocks don't have a wedge shape variant already in the block list.)