Respuesta :

MattD
[tex]a^2=81|\sqrt{81}[/tex]
a=9
Perimeter:
4*a=4*9=36cm
If it's a square, both sides are equal, and both sides must times together to get 81 :)
The square root of 81 is 9.
9 times four ( for the four sides) gives you 37cm^2 ;)