Question

A chess board contains 64 equal squares and the area of each square is 6.25 ????????^2. a border round the board is 2 cm wide. find the length of the side of the chess board.

Answer 1

Answer :-

☆ Length = 24 cm

Explanation :-

☆ Let the length of the side of a chessboard be x cm.

● Area of 1 square in chessboard= 6.25 cm²

♧ area of 64 squares= 64 × 6.25

♢ Area of 64 square = (x - 4)²

♡ 64 × 6.25 = (x - 4)²

☞ 400 = (x - 4)²

☞ 400 = x² +16 -8x

☞ 400 -16 = x²+16

☞ 384 = x²+16

☞ x² +16 -384 = 0

☞ x² -24x +16x -384= 0

☞ x(x -24) + 16 ( x - 24) = 0

☞ (x -24) (x +16) = 0

☞ (x -24) = 0  or  (x +16) = 0

☞ x = 24  or   x= -16

☆ Hence the Length of the side of the chess board= 24 cm.