Question

15.The sides of a rectangle are in the ratio 5:4 and its perimeter is 90 cm. Find its
Length and breadth.​

Answer 1

Answer:

Length of rectangle is 25 cm

Breadth of rectangle is 20 cm

Step-by-step explanation:

L is 5x and B is 4x

perimeter of rectangle = 90 cm

2 ( L + B ) = 90

L + B = 90 / 2

5x + 4x = 45

9 x = 45

× = 45 ÷ 9 = 5

Length (L) = 5x = 5 × 5 = 25 cm

Breadth (B) = 4x = 4 × 5 = 20 cm

Answer 2

❍ Let's Consider the Length and Breadth of Rectangle be 5x and 4x respectively.

As, We know that ,

$\star \boxed {\pink{\sf{ Perimeter _{(Rectangle)} = 2 (l + b) }}}$

Where,

• l is the Length of Rectangle and b is the Breadth of Rectangle.

⠀⠀⠀⠀⠀⠀$\underline {\frak{\star\:Now \: By \: Substituting \: the \: Given \: Values \::}}$

$\qquad:\implies \sf{90 = 2(5x + 4x ) }$

$\qquad:\implies \sf{\cancel {\dfrac{90}{2}} = 5x + 4x }$

$\qquad:\implies \sf{45 = 5x + 4x }$

$\qquad:\implies \sf{45 = 9x }$

$\qquad:\implies \sf{\cancel {\dfrac{45}{9}} = x }$

⠀⠀⠀⠀⠀$\underline {\boxed{\pink{ \mathrm {  x = 5\: cm}}}}\:\bf{\bigstar}$

Therefore,

• Length of Rectangle is 5x = 5 × 5 = 25 cm .
• Breadth of Rectangle is 4x = 5 × 4 = 20 cm .

Therefore,

⠀⠀⠀⠀⠀$\therefore {\underline{ \mathrm { Hence,\: Length \:and\:V|\:Breadth \:of\:Rectangle \:is\:\bf{25\: cm\:and\:20cm}}}}$

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$\large {\boxed{\sf{\mid{\overline {\underline {\star More\:To\:know\::}}}\mid}}}$

• $\begin{gathered}\boxed{\begin {array}{cc}\\ \dag\quad \Large\underline{\bf Formulas\:of\:Areas:-}\\ \\ \star\sf Square=(side)^2\\ \\ \star\sf Rectangle=Length\times Breadth \\\\ \star\sf Triangle=\dfrac{1}{2}\times Breadth\times Height \\\\ \star \sf Scalene\triangle=\sqrt {s (s-a)(s-b)(s-c)}\\ \\ \star \sf Rhombus =\dfrac {1}{2}\times d_1\times d_2 \\\\ \star\sf Rhombus =\:\dfrac {1}{2}p\sqrt {4a^2-p^2}\\ \\ \star\sf Parallelogram =Breadth\times Height\\\\ \star\sf Trapezium =\dfrac {1}{2}(a+b)\times Height \\ \\ \star\sf Equilateral\:Triangle=\dfrac {\sqrt{3}}{4}(side)^2\end {array}}\end{gathered}$

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