Follow the mark

Fold along the shared edges of the net. Each mark stays attached to its face and turns with it. In these cube drawings, the front face appears on the left.

Follow the edge a triangle points toward, or the edge beside a shaded half. After folding, the mark still faces the same neighbouring face.

Both cubes below come from this net. The triangle keeps pointing toward the ring as the whole cube turns. Use that shared edge as your reference; the triangle’s direction on the screen can change.

First check the faces. A and B both have the triangle on top, the ring on the front and the half-shaded square on the right. Their order around the corner is the same.

In the net, the triangle points down toward the edge shared with the ring. After folding, its tip still points toward the ring on the front face. Cube A keeps this direction.

Cube B turns only the triangle halfway around on its face, so its tip points away from the ring. Turning the whole cube cannot produce this change while leaving the other faces in place.

This net has a new arrangement of marks. Compare the shaded half in A and B. Check which neighbouring face it stays next to when the net folds.