Select the alternative which represents three out of the five alternative…

Concept: In a figure-fitting/reconstruction puzzle, the target outline is divided by irregular internal lines into a few regions. To identify which three of the five offered pieces reassemble the shape, match each piece's boundary (its straight segments AND jagged notches, in both length and angle) to the corresponding internal line of the target — two pieces can be neighbours only where their shared edge is identical in shape. The correct triplet, joined edge-to-edge in the right orientation, must reproduce the target outline exactly, with no gaps or overlaps.

Application: The target square's interior is cut by one line running from a point on the top edge down to a central meeting point, continuing as a small notch down to the bottom-left corner, and by a second line from that same meeting point up to the top-right corner. This creates three regions — a slanted piece on the upper-left, a double-notched piece filling the lower boundary, and a piece bounded by the diagonal on the right.

• Figure (1)'s pointed, single-notched edge matches the line running from the top edge down to the central point and on to the bottom-left corner.

• Figure (3)'s double-peaked, single-valley edge matches the small notch at the centre, closing the lower boundary exactly.

• Figure (4)'s slanted top edge matches the diagonal running from the centre point to the top-right corner.

Cross-check: Figures (2) and (5) are left over — figure (2)'s notch points the wrong way relative to this boundary, and figure (5)'s plain single straight edge cannot reproduce any of the jagged internal lines, so neither can substitute for figures (1), (3), or (4). Fitting (1), (3), and (4) together therefore reconstructs the square with no gaps or overlaps.

Hence, figures (1), (3), and (4) — option 134 — form the complete square.