Question

23. The area of a square is 81 cm². Find its perimeter and the length of its diagonal .​

Answer 1

Answer:

sq : 81 cm2

a*a=81

a=9=length

p=4a

p=4*9

p=36

Answer 2

Given,

• Area = 81 cm²

We know,

• $\boxed{\bold{\sf{Area \ of \ a \ square=a^2 \ \ \ \ [a=length]}}}$

Applying the value to the equation,

$\sf{\implies a^2=81}$

$\sf{\implies a=\sqrt{81}}$

$\sf{\implies a=9 \ cm}$

$\boxed{\bold{\sf{\therefore Length \ of \ diagonal=9 \ cm}}}$

We know,

• $\boxed{\bold{\sf{Perimeter \ of \ a \ square \ (P)=4\times a }}}$

Applying the value to the equation,

$\sf{\implies P=4\times 9}$

$\sf{\implies P=36 \ cm}$

$\boxed{\bold{\sf{\therefore Perimeter \ of \ square=36 \ cm}}}$