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 cm2 = 256 cm2
Thus, area of ∆BCD = 256 cm2
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 cm2, for shade II
= 256 cm2 and for shade III = 17.92 cm2 Ans.