Symmetry is when you split an object with a line of symmetry into two precisely similar parts. So, if I have a circle and draw a line of symmetry in its middle, I would be able to split the circle into two identical parts. Those similar parts are symmetry. An object or a structure when cutting into two halves giving the same structure of equal length is called symmetry, and the line which passes through them is the line of symmetry. We see many structures, objects and figures etc. which are evenly balanced and in pleasing proportions, by merely having a look at them we get to know that they are symmetrical. Some of the live examples are Taj Mahal and India Gate etc. These structures are beautiful because of their symmetry.