There is a difference between whether God can change a square into a circle and a ‘square-circle’.
I think there may be an answer in that there is beauty in Truth, in God. God’s creation was made to be good and He was pleased (sin adds death, decay and imperfection). And so there is an order which points to Him in order that human’s might find Him. In order for there to be an order there have to be rules and within time we are subject to mathematical rules. God is outside of time. So in our time a square is a square and a circle is a circle. And we have named the elements which make up this higher ordering of the Universe. So in order to understand God and His Universe, although people may not understand it is God they are searching for, have named, and we use those ordered named elements, that all point to God (all things came through Christ) to find the beauty in Truth and vice-versa. People could not find God if all there was, was chaos. God is everything good and all things good have meaning and in order for all things to have meaning there has to be an ordering of things that point to love for us to recognise His meaning. As human beings we recognise patterns and therefore structures and all the ways that enable us to build upon a memory of and a mental processing for the stimuli we perceive.
Now maybe there is a square-circle but we have not found it or recognise it but we live in time, we live within the mathematics of our Universe as human beings, so if mathematical shape A equals mathematical shape A and mathematical shape B equals mathematical shape B and they have different mathematical points that cannot go together then we cannot have them combined because to do so would be to undo God’s beautifully ordered Universe set up to see Him in the beauty and so he would have to have created chaos for this shape to exist. We know that chaos is not made by God. Chaos is the
without. To create such an imbalance would be to undo the order of things and so in essence this could be considered evil because it would throw the whole of existence into the abyss. But God is the God of love (He is Love) so why would He want to do that?
However, taking the time construction we have been placed in look at the London underground symbol - it is a circle and a rectangle combined. Stick a square instead of a rectangle in there and within time with the names things have been given this is the best we could do.