 Hello and welcome to the session. In this session we will determine types of symmetries for various geometric shapes. Now, symmetry is when one shape becomes exactly like another if you flip, slide or turn it. There are basically four types of symmetries for geometric shapes and these are reflection, translation, rotation and glide reflection. First of all we are going to discuss about reflection symmetry. The simplest symmetry is reflection symmetry, sometimes called line symmetry or mirror symmetry. A reflection can be thought of as getting a mirror image. It has a line of reflection. Here in this figure we can see that this is the line of reflection. This line can be viewed as the line on which the mirror will set in order to see the reflection of an image. Reflection takes place along an axis running through the figure. A figure has reflection symmetry if it is invariant after reflection. Reflection is a result of a figure flipped over a line. Now let us discuss an example. When we folded this figure along the green coloured line, the part of figure on one side of the green coloured line falls exactly over the other part. That is the green coloured line divides each figure into two coincident parts and these two parts are called mirror images of each other. Such figures are said to be symmetry figures and this green line is called line of symmetry. So line of symmetry is a line on which a figure can be folded so that both sides match. Here we can see that an equilateral triangle has three lines of symmetry. Similarly a square has four lines of symmetry and a circle has infinite lines of symmetry. Now we are going to discuss about translation. It is an actor sliding a figure in any direction to translate an object means to move it without rotating or reflecting it. Every translation has a direction and a distance. Let us consider an example. Here we have this image before translation and when we translate this image in this direction covering this much distance we get this image. So here we have this image after translation. Now we are going to discuss rotation. Rotation in a plane is around a fixed point. The center of rotation whether that point is part of the figure rotated or outside it. Any regular polygon be it an equilateral triangle or a square etc. has rotational symmetry around its center point. To rotate a figure means to turn it around and every rotation has a center and an angle. Here the given triangle is rotated about a fixed point P at an angle theta. Now we are going to learn about glide reflection. It combines both a reflection and a translation. It is composition of a plane that concepts of a line of reflection and a translation in the direction of the line of reflection performed in either order. In the figure the triangle on the right is reflected across the line of reflection and then translated downwards. Thus in this session we have learnt types of symmetries for various geometric shapes. This completes our session. Hope you enjoyed this session.