PLZZZ HELPPPP ILL MARK BRAINLIEST TO FIRST AND CORRECT ANSWER THAT HAS WORK AND A THX TO SECOND AND CORRECT ANSWER.

Answer:
well I think it is none of these because the square root would be 9^2
Step-by-step explanation:
Answer:
9^2
Step-by-step explanation
if the are is 81 then you have to think for th numbers like if the are was 20
it would be 5x4=20cm sorry i can't type in anything special ti won'y let me