Question

the ratio of length and breadth of a rectangle is 3:1 ,and it's perimeter is 36 cm . find the length and breadth of rectangle​

Answer 1

Answer:Length=13.5 and Breadth=4.5

Step-by-step explanation:See they said in the ratio of 3:1

So, length=3x

breadth=1x

Perimeter of rectangle=2(l+b)

Perimeter =36

Now,

36=2(3x+x)

36=2(4x)

36=8x

x=36/8

x=4.5

Length(3x)=13.5

Breadth(x)=4.5

Answer 2

SoluTion :-

Ratio = 3:1

Perimeter = 36 cm

Length = 3x

Breadth = 1x

$\boxed {\sf {\because \ Perimeter \ of \ a \ rectangle =2(l+b)}}\\\\\\\sf {\therefore \ 36 \ cm = 2 (3x + 1x)}$

$\sf {\Rightarrow 36 \ cm = 6x + 2x}\\\\\\\sf {\Rightarrow 36 \ cm = 8x}\\\\\\\sf {\Rightarrow x=\frac{36}{8}}\\\\\\\sf {\Rightarrow x = 4.5\ cm}$

Breadth = 1 × 4.5 = 4.5 cm

Length = 3 × 4.5 = 13.5 cm

Verification :-

36 cm = 2 (l + b) cm

36 cm = 2 (4.5 + 13.5) cm

36 cm = 2 (18) cm

36 cm = 36 cm