Q20 of 97 Page 780

Find the length of the diagonal of a square whose area is 128 cm2. Also find the perimeter.

Given:


Area = 128 cm2



Let the side of square be s


Area of square = 1/2 × Diagonal2


⇒ 128 = 1/2 × Diagonal2


⇒ Diagonal2 = 2 × 128


⇒ Diagonal2 = 256


⇒ Diagonal= 16 cm


Area of square = side2


⇒ 128 m2 = s2


⇒ s = 8√2 cm


⇒ s = 11.28 cm


Therefore,


Perimeter of square = 4 × 11.28


= 45.12 cm


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