ABCD is a square.

So, AO = OC = OB = OD

and ∠AOB = 90° [Diagonals of a square bisect each other at right angles]

BD = 32 cm (Given) ⇒ OA = 32/ 2 cm = 16 cm.

∆ABD is a right triangle.

So, area of ∆ABD = 1/ 2 × base × height

= 1/ 2 × 32 × 16 cm^{2} = 256 cm^{2}

Thus, area of ∆BCD = 256 cm^{2}

For triangle CEF, a = b = 6 cm, c = 8 cm.

∴ s = a + b+ c/ 2= 6+ 6+ 8/ 2 cm = 10 cm

∴ Area of the triangle

Hence, paper needed for shade I = 256 cm^{2}, for shade II

= 256 cm^{2 }and for shade III = 17.92 cm^{2} Ans.