Question 448919
To get the maximum enclosed area you should bend the wire in circle's shape, because all these geometric shapes can circumscribed in the circle, thus their area is always smaller than the area of the circle.

For example the area of the square will be:{{{(50/4)^2=50^2/16}}}, while the area 

of the circle will be:{{{pi*(50/(2*pi))^2=50^2/(4*pi)=50^2/12.56}}}, if we 

compare,{{{50^2/16<50^2/12.56}}}.