A box shows a circle on top, a triangle on the left face and a square on the right face. Which of the nets (a) to (d) is the net of this box?

In net (c) the circle and the triangle are the two ends of a row of three, so they would be opposite and could not be seen together. Nets (a), (b) and (d) all bring the circle, triangle and square together at one corner, but only in (b) do they go round that corner in the same order as on the box. (a) and (d) give its mirror image.