Hi,
Area of sector = angle subtended at center/360 x area of circle
30/360 = 1/12. Hence the 12 in the denominator
Hope this helps

Hi, the area of the sector is $$\frac{30}{360}\pi\ r^2$$ this is the area where the cow can't grace. So, we have to subtract it from total area of circle.

Hope this helps.

Hi Sanjana. We cannot do that, as the rest of the area of the circle is not relevant to the triangle. We find out the area of the segment by dividing the total area by 12, as the angle is given as 30$$^{\circ\ }$$. Since the total angle for a circle is 360, we get the area of the sector by dividing the total by 12, as 12 times 30 is 360. Hope this helps.

Hi Ashish Patel,
Area of the sector of a circle = $$\frac{\theta}{360}\times\ \pi\ r^2$$
It is given, $$\theta=30^{\circ\ }$$
Area = $$\frac{30}{360}\times\ \pi\ r^2$$ = $$\ \frac{\ \pi\ r^2}{12}$$
Hope this helps!