[previous configuration] [up to this 3D shape] [next configuration] ― Configuration code: RRmUmLmDUmLmDm

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• Start from the boomerang solution shape ,
• Place it with the missing corner at up-right position and the lower-left tile of "backslash" type.
• Turn down 180 degrees the upper row of two tiles (valley fold)
• Turn left 180 degrees the right column of two tiles (valley fold).
• We obtain a 2x2 square with three stacked tiles in the upper-right position and two pair of two stacked tile in the two adjacent positions.
• Switch the hinging side of these two piles of two stacked tiles and open carefully into the final shape