Three blocks, called AAA, BBB and CCC exist in the image. A big black square is inside and touching block AAA. Block AAA contain a medium blue triangle and a medium black triangle. The medium black triangle is north of the big black square and is close to the medium blue triangle. Block BBB cover a small yellow square, a big blue triangle and a big black square. The big blue triangle is north of the big black square.
What is the position of the big black square covered by BBB regarding the big blue triangle?