Let original length = x metres and original breadth = y metres.

Original area = (xy) m².

New length = \(\left(\frac{120}{100}x\right)m=\left(\frac{6}{5}x\right)m.\)

New breadth =  \(\left(\frac{120}{100}y\right)m=\left(\frac{6}{5}y\right)m.\)

New Area = \(\left(\frac{6}{5}x\times\frac{6}{5}y\right)m^{2}.=\left(\frac{36}{25}xy\right)m^{2}\)

The difference between the original area = xy and new-area 36/25 xy is

= (36/25)xy - xy

= xy(36/25 - 1)

= xy(11/25) or (11/25)xy

So, Increase % =    \(\left(\frac{11}{25}xy\times\frac{1}{xy}\times100\right)\)  %= 44%