Question

what will be the cost of fencing rectangular compound if the wire cost 20 rs per meter area 40 m^2 b length =2*breadth

Answer 1

According to question

Area of rectangular compound   A = 40 m^2

Given that     l = b * 2

Thus  area   A = l * b
                    40 = 2 b^2
So                 b = root 20
                     b   = 2 root 5

And      l = 2 *  b
             l = 2 * 2  root 5
             l = 4 root 5

So   Total length of compound = 2 ( l+ b )
                                                 = 2 ( 6 root5 )
                                                 = 12 root 5
Thus cost  = 12 root 5 * 20 
                   = 240 root 5 Rs 

Answer 2

Given:
Area of rectangular Compound= 40 m²
Length = 2 × breadth
Area of rectangle = 40 m²
length × breadth = 40m²
2 × breadth × breadth = 40m²
Breadth² = 40/2= 20 m
Breadth = √20 m
Length = 2 × Breadth = 2 ×√20 m
Length = 2√20 m
Perimeter of rectangle = 2(length + breadth)
= 2(2√20 + √20) m
= 2(3√20) = 6√20 m = 6 × 4.47 m = 26.8 m
Rate of the wire = ₹ 20 per m
Cost of fencing the rectangular compound = 26.8 × 20= ₹ 536
Hence, the Cost of fencing the rectangular compound = ₹ 536 .
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