Question

the perimeter of a rectangle is 50cm its area will be decreased by 6cm if length is decreased by 3cm and breadth is increased by 2cm find the dimensions of rectangle
plzz ans fst......​

Answer 1

My dear friend,

The perimeter of a rectangle is 50 cm its area will be decreased by 6cm if length is decreased by 3 cm and breadth is increased by 2cm find the dimensions of rectangle?

$SolutioN:-$

Method 1 :-

Given data :- The perimeter of a rectangle P = 60 cm

Find out :- The length of the rectangle L = ?

The breadth of the rectangle B = ?

If the length is increased by 3 cm the length = ( L + 3 ) cm

Then the breadth decrease by 3 cm = ( B - 3 ) cm

Then their length and breadth are in the ratio = 2:1

$\frac{L+3}{B-3}$ = 2:1

( L + 3 ) = ( 2B - 6 )

L = 2B - 9—————----------(1)

Perimeter of the rectangle = 60cm

2 ( L+B ) = 60

  ( L+ B ) = 30

Just substitute the value of L from the equation ( 1 ) we get,

2B - 9 + B = 30

3B = 21

B = 7cm answer. So, the breadth of the Rectangle = 7 cm.

The length of the rectangle L = 2B-9= ( 2×7 cm - 9 ) = 5 cm. Answer.

Method 2 :-

In the rectangle L+B = $\frac{60}{2}$ = 30 cm.  

Or B = 30-L.

(L+3): (30-L-3) = 2:1, or

(L+3): (27-L) = 2:1, or

L+3 = 2(27-L), or

L+3 = 54 - 2L, or

3L = 51, or

L = 17 cm and B = 13 cm.

Check: ( 17 + 3 ):( 13 - 3 ) = 20:10 or 2:1. Correct.

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Thankyou,

Best regards,

°⑅ ❤〜 ₙₙ Mileyₙₙ 〜❤ ⑅°

Answer 2

Answer:

the length is 30 cm and breadth is 20 cm

Step-by-step explanation:

l+b=50 (eq 1)

(l-3)(b+2)=lb-6cm

lb+2l-3b-6=lb-6

2l-3b=0 (eq 2)

multiply eq 1 with 2 = 2l+2b=100

2l-3b=0

2l+2b=100

-. +. -.

_________

-5b=-100

b=20cm

l+ 20 cm = 50

so l =30 cm