Area of square = 64 sq cm (Side)2 = 64 ? Side = ?64 = 8 cmAccording to the question,? 2?r = 4 x 8 ? r = (4 x 8)/2?? r = 16/?? Area of the circle = ? x (16/?) x (16/?) sq cm = 256/? sq cm.
Let original length = x and original breadth = y. Decrease in area = xy - ❨ 80 x x 90 y ❩ 100 100 = ❨ xy - 18 xy ❩ 25 = 7 xy. 25 ∴ Decrease % = ❨ 7 xy x 1 x 100 ❩% = 28%