01
Label six squares before folding
The flat arrangement has five shared edges: A with B, B with C, C with D, B with E and B with F. Those are the initial fold connections. Six squares contain twenty-four individual edge segments before shared boundaries are counted. Removing two segments for each of the five shared edges leaves fourteen boundary segments around the flat net. This perimeter count is measured in square-side units. It is not the number of distinct edges on the folded cube, which is a different object with twelve distinct edges.
02
Track neighbours and opposite faces
Hold B as the front face. Folding the adjacent faces around it places A opposite C and E opposite F. The remaining square D folds around from C to become opposite B. Record the three opposite pairs as A–C, E–F and B–D. Faces that touch in the flat net stay connected, but other faces meet only after folding. This is why the two-dimensional picture alone can be misleading. The labelled model makes the new relationships visible without relying on an unlabelled mental rotation or guessing which face has moved behind another.
03
Build a numbered paper reference
Draw the six squares on scrap paper, mark the letters and fold the connected shape into a cube. Check each claimed opposite pair by looking through the model before closing the last face. If glue tabs are added, draw them as separate features so they are not mistaken for extra faces. Keep a photograph or sketch of the labelled result beside the original net. The reusable record has three parts: flat adjacency, opposite pairs and any construction notes discovered while making the paper reference.