"application of minima and maxima " can someone please help me on how will i discuss this problem orally?

This I think is a badly worded question as to ask for a shape and then state it is a rectangle is rather odd, but I think it is asking for the dimensions of the rectangle. Therefore if you think of the rectangle as a square with sides of 4 and 4 then the fencing will be 4 x 4 giving 16 and the area would also be 16. Now if we look at a rectangle with the same area of 16 with two sides of of 8 and two sides of 2 then the area would be the same, but the perimeter fencing would be 8+8+2+2 = 20. WE can therefore say that as the rectangle becomes longer eg two sides 16 and two sides 1 the perimeter gets longer 16+16+1+1 = 34. So from this we can say that the minimum perimeter would be as a square and the maximum would be a very long but narrow rectangle.