Question

find the length and the perimeter of a rectangle if its breadth is 20mm and the area is 1000sq.mm​

Answer 1

Answer:

Let the length be assumed as = x

$\color{black}\boxed{\colorbox{saffron}{Area - length×breadth}}$

${1000}^{2} = {20}^{2} \times {x}^{2} \\ \\ = \frac{1000}{20} = x \\ \\ = x = 50 \: mm$

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So, as we know that the length is 50 mm, we will find the Perimeter.

$\color{black}\boxed{\colorbox{saffron}{Perimeter-2(length+breadth) }}$

2(20+50)

= 2(70)

= 140 mm

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Required Answer -

$\rightarrow$length=50 mm

$\rightarrow$Perimeter = 140mm

Answer 2

Answer:

area of rectangle = l x b

1000sq.mm=l x 20mm

l= 1000 sq.mm/20mm

l=50 mm

perimeter=2(l+b)

=2(20mm+50mm)

=2(70mm)

=140mm