what is the square root of 168,921 ?
"1 ) checking the last digits in the answer options a , c , e are out since last digit of the square is known to be 1 . 2 ) b = 389 ^ 2 and d = 411 ^ 2 b = ( 400 - 11 ) ^ 2 and d = ( 400 + 11 ) ^ 2 since we need the answer less than 160000 = > b is out . thus we have d as the ans ."
circle_area(divide(168,921, multiply(const_2, const_pi)))