The area of a circle is derived as
Area = πr²
Where π is 3.14 and r is 11 cm
For a sector, which is a portion of the entire circle, you can derive the area by calculating the portion of the whole circle using the angle at the center of the circle as the ratio of the portion. This means, if the angle at the center of the sector is 30 degrees (as shown), then the area of the sector is a portion shown by area of the circle times 30/360 (this is usually depicted as
Area = (θ/360) * πr²
Hence the area of the circle shown is calculated as follows;
Area of sector = (30/360) * 3.142 * 11²
Area of sector = 1/12 * 3.142 * 121
Area of a sector = 31.68183333...
Area of the sector (is approximately) = 31.7 cm²
