Question

the length of a rectangle is twice it's breadth.the perimeter of the rectangle is 120cm.find the length and breadth of this rectangle

Answer 1

hi,

here is the solution
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let the bredth be x
and length be 2x

so,
ACCORDING TO QUESTION
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perimeter of rectangle:--
==>2 ( L + B ) = 120

==>2 ( 2x + x ) = 120

==>4x + 2x = 120

==>6x = 120

==>x = 120/6

==>x = 20
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SO,

bredth is 20 cm
and length is 20×2 = 40cm

Answer 2

$\large{\red{\underline{\underline{\textsf{\maltese\:{\red{Given }}}}}}}$

$\sf{Length \:of \:a\: rectangle\: is\: twice \:it’s \:breadth}$

$\sf{The \:perimeter \:of\: the\: rectangle\: is\: 120\:cm}$.

$\large{\red{\underline{\underline{\textsf{\maltese\:{\red{To\:Find }}}}}}}$

$\sf{Length = ?}$

$\large{\red{\underline{\underline{\textsf{\maltese\:{\red{Solution:}}}}}}}$

$\sf{Let,\:the\: Breadth\:of \:the\: rectangle\: (b) = a}$

$\sf{The\: Length\: of\: the\: rectangle\: (l) = 2a}$

$\sf{The \:Perimeter \:of \:the \:rectangle = 120 c.m}$

$\sf{⇒ 2 (a + 2a) = 120}$

$\sf{⇒ 2 (3a ) = 120 }$

$\sf{⇒ 6a = 120}$

$\sf{⇒ a = \dfrac{120}{ 6}}$

$\sf{⇒ a = 20}$

$\sf{The\: Breadth\: of\: the \:rectangle = 20\: c.m}$

$\sf{The \:Length \:of\: the \:rectangle = 2a}$

$\sf{⇒ [2 (20) ]\:c.m}$

$\sf{⇒ 40\: c.m}$

$\sf{Hence,\: the\: length\:of \:the\: rectangle \:is\: 40\: c.m}$