Q8 of 227 Page 107

A chess board contains 64 equal squares and the area of each square is 6.25 cm2. An order around the board is 2 cm wide. Find the length of the side of the chess board

Let x be the side length of the square board


Area of one square in the chess board = 6.25cm2


Area of 64square = 64×6.25


(x – 4)2 = 400


⇒ x – 4 = √400


⇒ x – 4 = ± 20


x – 4 = 20 or x – 4 = –20


x = 20 + 4 or x = –20 + 4


x = 24 or x = –16


Therefore, side length of square shaped chess board is 24cm.


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