The Celtic triangle. or triple knot. was believed to create an unbreakable circle of protection. It symbolizes the fact that the physical. mental and spiritual are all interwined. It is a matter of... The need for protection knows no geographical or cultural limits. When there is evil that surrounds you. it is best to get some protection. whether it is circle. pentagonalprism. or a polygon that looks like a trapezoid. As our elders said. you are either in the circle or outside the circle. It is all a matter of self-protection.