The square root of 0.81 is

0.9

To find the square root of 0.81, follow these steps:

Step 1: Start with the number 0.81.

Step 2: Try to find a number that, when multiplied by itself, equals 0.81.

Step 3: Since 0.9 multiplied by itself equals 0.81, the square root of 0.81 is 0.9.

Therefore, the square root of 0.81 is 0.9.