How to construct a squre when .....?

s + d = 6.2
d – s = 1
2d = 7.2
d = 3.6
draw line segment of 3.6 cm AB
draw perpendicular bisector MON
O is midpoint of AB
draw circle with O as center and OA or OB as radius
The perpendicular bisector of AB cut the circle at M and N
Join AM, MB. BN, NA
AMBN is required square

side of square 2s² = 3.6²
s = 3.6/√2 = 1.8√2
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s^2 + s^2 = c^2
2s^2 = c^2

s + c = 6.2
c = 6.2 - s

2s^2 = (6.2 - s)^2

2s^2 = (6.2 - s)(6.2 - s)

2s^2 = 38.44 - 6.2s - 6.2s + s^2

2s^2 = 38.44 - 12.4s + s^2

s^2 + 12.4s - 38.44 = 0

s = (-12.4 ± √307.52) / 2
ignore negative solution
s = 2.5681240867131893025704700901001 cm