Question

10. A rectangle has its area equal to that of a square of side 80 cm. If the breadth of the rectangle is
20 cm, find its length.​

Answer 1

the length of the rectangle =

2 x 20 + 2 x x = 80 =

40 = 2x = 80     =

2x = 80 - 40

x = 20

Answer 2

Question:-

A rectangle has its area equal to that of a square of side 80 cm. If the breadth of the rectangle is

20 cm, find its length.

Solution:-

Given,

Side of square = 80 cm

Breadth of rectangle = 20 cm

Area of square = side × side

$= 80 \times 80 \: {cm}^{2}$

$= 640 \: {cm}^{2}$

According to question,

Area of rectangle = Area of square = 640 cm^2

Therefore,

$length \times breadth = 640 \: {cm}^{2}$

Given, breadth = 20 cm

So,

$length \times 20 \: cm = 640 \: {cm}^{2}$

$length = \frac{640 \: {cm}^{2} }{20 \: cm}$

$length \: = 32 \: cm$

Formulae :-

Area of Rectangle = length × breadth

Area of square = side × side