Respuesta :

Jieep
Square root of 81 is 9. 
Each side is 9 cm. 

9 times 4 (4 being the sides of the square) = 36 

Perimeter=36
the answer for ur question is 
 it is given that it is a square

so, the square root of 81 is 9
so for each it will be 9cm 
so,9*4 =36 

so the perimeter is 36

HOPE THIS HELPS U!