The correct option is C more than Rs. 500
In an isosceles right angled triangle, the two sides on the right angle are equal.
Hence, hypotenuse of the isosceles right angled triangle of side a=√a2+a2=a√2
Given, a√2=50√2
a=50
Hence, length of the other two sides of the triangle is 50 m
Perimeter of the triangle =50+50+50√2=100+50√2=100+50×1.414=100+70.7=170.7 m
Cost of fencing it at Rs. 3 per m=3×170.7= Rs. 512.1
Hence, the cost of fencing is more than Rs. 500