Find the area of the shaded region in Fig. 12.20, if radii of the two concentric circles with centre O are `7` cm and `14` cm respectively and `/_A O C= 40^@`

Explanation

To find the area of the shaded region between two concentric circles with radii 7 cm and 14 cm, and an angle of \(40^\circ\) at the center, we will follow these steps:

### Step 1: Calculate the area of the sector AOC
The formula for the area of a sector is given by:
\[ \text{Area of sector} = \frac{\theta}{360^\circ} \times \pi r^2 \]
where \(\theta\) is the angle in degrees and \(r\) is the radius of the circle.
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