[up to this 3D shape]
- Start from
- Flatten into a 3x2 rectangle with two stacks of two tiles in the central row
- Position it such that the higher tiles of the two stacks are flaps that can
be rotated about their south side
- Actually rotate 90 degrees the western flap (in an upright position)
- Rotate 90 degrees a pair of adjacent tiles about their west side (valley fold)
into the final shape
Also, this is hinge equivalent to 
