Which Face Is Opposite?

Six marked squares lie flat. The dot sits in the centre, with a triangle above, a ring right, a stripe below, a diamond left, and a cross on the tail. Watch them fold... The marks travel with their faces, and one face ends up hiding directly behind the dot.

Fix your eyes on the dot face. As the fold pauses halfway, four hinged faces rise around it: triangle, ring, stripe, and diamond. Each one meets an edge of the dot. That makes all four neighbours, so none of them can be opposite the dot. Now the cube closes, and only the cross face remains. It never touches the dot. It closes across from it, so dot and cross are opposite. On this net, the other opposite pairs are triangle with stripe, and ring with diamond. Do not judge by distance on the flat net. Two faces can look far apart and still become neighbours. Fold mentally, name the four faces that touch your target, then choose the ONE face left.

Let's work through an example. The complete marked net is open again. Which marked face will be opposite the centre dot after folding? Choose between Option A, the triangle; Option B, the ring; Option C, the diamond; and Option D, the cross. Which option is correct? Start by fixing the dot. The triangle folds up and touches its top edge, so eliminate Option A. The ring touches the right edge, so eliminate Option B. The stripe touches the bottom edge, although it is not an option. The diamond touches the left edge, so eliminate Option C. Four touching faces are now accounted for. The cross is the only face left. The cube closes, the dot stays fixed, and the cross lands directly opposite it. Option D is correct.

Remember: fix the target, find its four touching neighbours, then choose the remaining face as opposite. Keep the marks attached while the net folds. You can track every face with confidence!