A wire of length 100cm is cut into two pieces of length xcm and ycm. The piece of length xcm is bent into the shape of a square and the piece of length ycm into the shape of a circle. Find x and y so that the sum of the areas encloseed by the shapes will be (a) a minimum (b) a maximum

I gathered that one of the equation will be x+y=100 but im not sure what the other equation will be, please help me with this? thanks