It will have to be a perfect square but you can use two of the square blocks and one straight piece on one side and one straight piece on the other

This gets you out of a tough situation, and the lines you clear during the collapse count towards your line total, however, it also cancles out any remaining bonus square sections

thats because there are a few frills added to this game that make it more interestingone, you can take 4 identical or differant tetroids and weave them together to form a solid 4x4 square and get bonuses when you clear a line containg a portion of the square

Good as we expected ,thanks