the area of a rectangular carpet is 120 m 2 and its perimeter is 40 cm the length of the diagonals is
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let the length of rectangle be x and breadth be y
then
area of rectangle = length * breadth
here, area of rectangle= l*b = lb
120 =l*b
120 = lb --------------------1equation
Now,
perimeter of rectangle = 2(l+b)
here, 40 = 2(l+b)
40/2= l+b
20 = l+b -----------------2equation
as by pythagoras theorem,
diagonal^2= l^2 +b^2
Now,
by formula (a+b)^2 = a^2 +b^2 +2ab
(l+b)^2 = l^2 + b^2 +2lb
putting the values from equation 1&2,
(20)^2 = l^2 + b^2 +(2*120)
400 = l^2 + b^2 +240
400-240 = l^2 + b^2
160 = l^2 +b^2 -----------------3equation
then
diagonal^2= l^2 + b^2
putting the value of l^2 +b^2 from 3equation
diagonal^2 = 160
then
diagonal = root 160
diagonal = 12.63 cm
i hope this will help you
-by ABHAY
abhi569:
if cost of fencing is 25
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Hlo friend.. Cutiepie Here...
Here is ur answer :
Area of a rectangular carpet = 120 m²
Let length be l and breadth be b.
Length × breadth = 120
lb = 120 ____________ (1)
Perimeter of Rectangular carpet = 40 cm
2 ( length + breadth) = 40
2 ( l + b) = 40
( l + b) = 40 / 2
( l + b) = 20 ___________(2)
Diagonal D of Rectangular carpet =
By using identity,
( a + b)² = a² + b² + 2ab
Putting the values from eqⁿ (1) and (2)
( l + b)² = l² + b² + 2lb
(20)² = l² + b² + 2(120)
400 = l² + b² + 240
l² + b² = 400 - 240
l² + b² = 160
Diagonal =
Diagonal D of Rectangular carpet = 12.64 cm.
________________
HOPE IT HELPS YOU..
Here is ur answer :
Area of a rectangular carpet = 120 m²
Let length be l and breadth be b.
Length × breadth = 120
lb = 120 ____________ (1)
Perimeter of Rectangular carpet = 40 cm
2 ( length + breadth) = 40
2 ( l + b) = 40
( l + b) = 40 / 2
( l + b) = 20 ___________(2)
Diagonal D of Rectangular carpet =
By using identity,
( a + b)² = a² + b² + 2ab
Putting the values from eqⁿ (1) and (2)
( l + b)² = l² + b² + 2lb
(20)² = l² + b² + 2(120)
400 = l² + b² + 240
l² + b² = 400 - 240
l² + b² = 160
Diagonal =
Diagonal D of Rectangular carpet = 12.64 cm.
________________
HOPE IT HELPS YOU..
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