Question

find the area of rectangle whose perimeter is 120 cm and length is 42 cm​

Answer 1

Answer:

Given ,

l = 42 cm

perimeter = 120 cm

perimeter of rectangle is given as 2 ( l+b )

2 ( l+b ) = 120

2 ( 42 + b ) = 120

84 + 2b = 120

2b = 120 - 84

     = 36

b = 36 / 2

  = 18 cm

area of rectangle = lb

                             = 42×18

                             = 756 cm²

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Answer 2

Answer:

The area of the Rectangle is 756 cm²

Step-by-step explanation:

Given :

Perimeter = 120 cm

Length = 42 cm

To find :

Its area

Solution :

Consider the breadth as x

★ Perimeter = 2(Length + Breadth)

$\longrightarrow$ 2(42 + x) = 120

$\longrightarrow$ 84 + 2x = 120

$\longrightarrow$ 2x = 120 - 84

$\longrightarrow$ 2x = 36

$\longrightarrow$ x = 36/2

$\longrightarrow$ x = 18

Breadth = 18 cm

$\rule{300}{1.5}$

★ Area = Length × Breadth

$\longrightarrow$ 42 × 18

$\longrightarrow$ 756

$\therefore$ The area of the Rectangle is 756 cm².