The length of a rectangle exceeds its breadth by 18 cm. If length and breadth are each increased by
6 cm. then area of the new rectangle will be 336 cm square more than that of the given rectangle. Find the
length and breadth of the given rectangle.
Answers
Let the Breath be x
Then,length=x+18
Increased length = x+18+6
= x+24
Increased Breath= x+6
Area of the given rect.= x*x+18
= x^2+18
Area of the increased rectangle=
(x+24)*(x+6)
=x^2 + 30x + 144
Now,Difference=336(given)
Therefore,(x^2+30x+144)-(x^2+18)=336
30x + 126 = 336
30x = 336 - 126
30x = 210
× = 210/30
= 7 cm.
Breadth of the given rectangle = x = 7 cm.
Length of the given rectangle. = (×+18)
= (7+18)
= 25cm. ANS.
Question:-
The length of a rectangle exceeds its breadth by 18 cm. If length and breadth are each increased by
6 cm. then area of the new rectangle will be 336 cm square more than that of the given rectangle. Find the
length and breadth of the given rectangle.
Solution:-
given:-
• The length of the rectangle exceeds it's breadth by 18 cm.
• If length and breadth is increased by 6 cm.
• Then area of new rectangle will be 336cm² more than given rectangle.
Find:-
• The length and breadth of the original rectangle = ?
Formula:-
=> Area of rectangle
= length(L) × breadth(B)
Now, by given,
let, x be the breadth of rectangle so,
for original rectangle.
• breadth = B1 = x ........ ( 1 )
• length = L1 = x + 18 ........ ( 2 )
so, now....
for new rectangle
• breadth = B2 = x + 6 ........ (3)
• length = L2 = x + 18 + 6 ....... ( 4 )
we know, that area of new rectangle will be 336cm² more than given rectangle.
so now,
=> (Area of new rectangle) - ( 336 cm² )
= (Area of oringinal rectangle)
=> (L2 × B2)+ 336 = L1 × B1
=>( x + 18 + 6 ) ( x + 6 ) - 336 = ( x + 18) ( x )
=> ( x + 24) ( x + 6 ) - 336 = x² + 18x
=> x² + 24x + 6x + 144 - 336 = x² + 18x
=> x² + 30x + 292 = x² + 18x
=> x² - x² + 30x - 18x - 292 = 0
=> 12x - 292 = 0
=> 12x = 292
=> x = 292/12
=> x = 24.33cm
From ( 1 ),
• breadth = x = 24.33cm
From ( 2 ),
• length = x + 18
• length = 24.33 + 18
• length = 42.33cm
From ( 3 )
• breadth = x + 6
• breadth = 24.33 + 6
• breadth = 30.33cm
From ( 4 )
• length = x + 18 + 6
• length = 24.33 + 22
• length = 46.33cm
Hence length and breadth of original rectangle are 42.33 cm
and 24.33 cm respectively.
and length and breadth of new rectangle are 46.33 cm and
30.33 cm respectively.
i hope it helps you.