Question

a rectangle has 30cm as its length and 720 sq.cm as its area . it's area is increased to 11/4 times it's original area by increasing only it's length . what will be the new perimeter?​

Answer 1

Answer:

[tex]Original breadth of rectangle

=72030=24 cm72030=24 cm

Now, area of rectangle

=54×720=900 cm254×720=900 cm2

Therefore, New length of rectangle = 2(l+b)2(l+b)

=2(37.5+24)=2×61.5=123 cm2(37.5+24)=2×61.5=123 cm

Answer 2

Answer:

Original breadth of rectangle = 720/30 = 24 cm

Now , 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