In the given figu

Given:

Radius of inner circle = 3.5 cm

Radius of outer circle = 7 cm

∠POQ = 30°

Let the sector made by the arcs PQ and AB be S₁ and S₂ respectively.

Then, Area of shaded region = Area of S₁ – Area of S₂ ………….(i)

∵ Area of sector = × πr²

∴ Area of S₁ = × × 7 × 7

= cm²

Similarly, Area of S₂ = × × 3.5 × 3.5

= cm²

Thus, using (i), we have

Area of shaded region = -

=

= = cm²

Hence, the area of shaded region is cm².