Question

perimeter of rectangle is 180 metre and its length is 10 metre more than its width find the length and with the answer NCERT solution​

Answer 1

Answer:

let the breadth be x

=>length = x+10

perimeter=2(l+b)

=>180=2(x+x+10)

=>90=2x+10

=>2x=80

=>x=40

Answer 2

GIVEN :

• Perimeter of rectangle = 180 metre
• Length is 10 metre more than its width.

TO FIND :

• Length of rectangle

FORMULA USED :

✦ Perimeter = sum of all sides

✦ perimeter of rectangle = sum of all sides of rectangle

we know that , opposite sides of rectangle are equal.

Therefore :-

$= > perimeter \: of \: rectangle \: = l + l + b + b$

$= > perimeter \: of \: rectangle \: =2 l +2 b$

$= > perimeter \: of \: rectangle \: = 2(l + b)$

✦ therefore , FORMULA of perimeter of rectangle => 2(l + b)

✦ where :- l = length and b = breadth/ width

SOLUTION :

⟹ Length is 10 metre more than its width

⟹ Let width be X

⟹ therefore length = X + 10 ( because it is given that Length is 10 metre more than its width)

✦ Perimeter of rectangle = 180 metre. ( given)

✦ Now According to the question =>

$⟹2(l + b) = 180$

put l = X + 10 and b = x

$⟹2(x + 10 + x) = 180$

$⟹2(2x + 10) = 180$

$⟹2 \times 2(x + 5) = 180$

$⟹x + 5 = \frac{180}{4}$

$⟹x + 5 = 45$

$⟹x = 45 - 5$

$⟹x = 40$

Therefore width/breadth(X) = 40 metres

Therefore Length = X + 10

$⟹l \: = 40 + 10$

$⟹l = 50m$

Therefore , Length = 50 metres

✦ ANSWER =

Length of rectangle = 50 metres

_______________________________

✦ More Formulae related to rectangle =>

1. perimeter of rectangle = 2(l +b)

2. Area of rectangle = l × b

where :- l = length and b = breadth