The area of the middle shadow part =4? -4{4? πx360 /30 -[4？ π/4-4? πx360 /30 -(4x2√3)/2]}

= 16-4[4π/3-(4π-4π/3-4√3)]

= 16-4(4√3-4π/3)

= 16- 16√3+ 16π/3

= 16( 1-√3+π/3)

= 16( 1- 1.73+ 1.05)

= 16x0.32

=5. 12 (square centimeter)

A: The shadow area is 5. 12 cm2. ?

The area corresponding to each part is as shown in the figure: