Your answer is 11.11 %. This is because 1/9th of a circle is actually its 1/9th part of the whole circle. Considering the circle as 100. 1/9th of 100 is 11.11%
The area of a circle is pr2 where (p=3.14) and r is the radius of the circle so 1/9 of a circle would be
1/9pr2.
1/9pr2.