Question

How to do it,because I do not know

Answer 1

check the picture below.

now, placing the band's members on those locations, gives us 4 quadrilaterals, if we fold the paper along the y-axis and then along the x-axis, namely vertically and horizontally like folding a letter, the quadrilaterals will over end up pancaked on each other, due the symmetry, namely one quadrant mirroring the other quadrant.