Area of park = 100 x 100 = 10000 m2Area of circular lawn = Area of park - area of park excluding circular lawn= 10000 - 8614 = 1386Now again area of circular lawn = (22/7) x r2 = 1386 m2? r2 = (1386 x 7) / 22= 63 x 7= 3 x 3 x 7 x 7? r = 21 m
Original breadth of rectangle = 720/30 = 24 cmNow , area of rectangle = (5/4) x 720 = 900 cm2? New length of rectangle = 900/24 = 37.5 cm? New perimeter of rectangle = 2(l+ b)= 2(37.5 + 24 ) = 2 x 61.5 = 123 cm