Question

12. The sides of a rectangle are 20 cm and 15 cm. If each side of the rectangle is increased by 20%, find the
percentage increase in the area.​

Answer 1

Answer:

Original area:

A1 = 20(15) = 300cm2

New area:

A2 = (20*1.2)(15*1.2) = 432cm2

% increase = (432 - 300)/300 x 100%

% increase = 44%

Answer 2

Given:

Length=20

Breadth=15

Solution:

Area=20×15=300

New length=20+(20%of 20)

                  =20+($\frac{20}{100}$×$20$)

                  =24.

New breadth=15+(20%of 15)

                     =15+($\frac{20}{100}$×$15$)

                     =18.

New area=24×18

                 =432

Difference=432-300=132

% of area increased=$\frac{132}{300}$×$100$

                                =44%

Answer:

44%