The Four Sided Triangle

The Four Sided Triangle is a perplexing conundrum. By definition, there is no such thing as a four sided triangle. Many people debate that the impossibility of a four sided triangle thus proves the existence of God. In that belief, the definition of a triangle (three sided shape) proves its existence. The same goes for the existence of God. The definition of God (supreme being, omnipotent etc) proves His existence. Furthermore, knowing what "triangle" means reflects that a four sided triangle is impossible. Similarly, knowing what "God" means shows that his non-existence is impossible. Therefore, God has to exist because four sided triangles are impossible. I told you this was perplexing. The four sided triangle is an old ontological argument stating that God exists just by thinking about it. So what do you think about it?