Edited by author 06.11.2008 19:04

for WA #4 try this triangles with pairwise parallel sides:

0 0 1 1 2 0
0 0 1 -1 2 0

Also

2 0 0 0 1 1
2 0 3 -1 4 0

2  0 0  0 1  1
2 -1 3 -2 4 -1

Angle is 180 for each case, the center or rotation you should easily find after drawing the triangles.