Question

(5) Find perimeter of a square if its diagonal 10√2 cm.
(A)10 cm (B) 402 cm (C) 20 cm (D) 40 cm​

Answer 1

Answer:

d) 40 cm sq.

Step-by-step explanation:

Given :-

Diagonal measure = 10√2

To Find :-

Perimeter of the square

Solution :-

Let ABCD be square with AC diagonal 10√2.

Now in ΔABC,

AB = x, BC = x and AC = 10√2.

Using Pythagoras theorem,

AB^2 + BC^2 = AC^2

x^2 + x^2 = ( 10√2 )^2

x^2 = ( 100 )

 x = √100 = 10

Therefore the sides of square is 10 cm

Now finding the perimeter,

= 4 x side  

= 4 x 10

= 40

Perimeter of this square = 40 cm sq.

Answer 2

The correct answer is - option D

EXPLANATION :

GIVEN :

Diagonal of a Square = 10√2 cm.

Perimeter of Square = ?

We know that,

Diagonal of Square = S√2

Side√2 = 10√2

Side = 10√2 / √2

Side = 10cm

Perimeter of Square = 4 × side

= 4 × 10

= 40cm

Therefore, Perimeter of Square is 40cm.