For the first problem a.k.a problem #33 I looked it up in downward direction. For each column we can see that there is a triangle that never “moves” (red circle) and that's our reference point and it follows the clockwise pattern . So we can expect that in the third column there will be a plain triangle at the upper left corner. The rest is finding the alternating triangle pattern start from the first column and I guess you can just follow it with few adjustments for the rest of the columns. 