 Welcome back to the session on latex. In this session, we will explore a new term called packages and we will learn to set paper size and margins. Well, latex helps us typeset the document in the way we want using the document class. But sometimes we do need a facility of extending and using the features defined in it. Packages help us resolve this. There are several packages that we can use in our document for different purpose. The syntax is slash use package and the package name. And it is mentioned before the document begins. You must be definitely aware of some standard paper sizes like A4, A5, letter, executive, etc. Well, one can set the paper size using the geometry package as shown here. Use package, A5 paper, geometry. Marginstoo are set using this geometry package. Let's see a demo. I am switching to text studio. I have a template open. Let us add some random text and sections. Section title is added. Let us add some random text. This is a latex document, which we want to build. Let's copy paste this multiple times and let us copy paste the sections. Let's build and run. So I get sections, page number 1, page number 2 and page number 3. Go on top. Now let's set paper size using the geometry package. So we write slash use package, geometry and we write the size of the paper. So A5 paper, build and run, yes. You see the paper size is reduced. So we have now one page, second page, third and the fourth. Let's change it to A3, build and run. If you see the entire page is now A3 with just two pages. Change it to A4, build and run. Yes, we have again come back to our default mode. Now let's come to margins. So just next to A4 paper, we will write comma margin equal to 1 inch, IN is a unit for inches. We build and run. So we can see, top, left, right and bottom, margins have been set for 1 inches. Let's change it to 2 inches, build and run. The margins of all the four sides have changed. Now let's assume that you want to set different margins. Say top you want 1 inches, left you want 2 inches, right you want 0.75, bottom some other. So how do you do that? You write top equal to 1 inch, comma, left equal to 2 inches, right equal to say 0.75 inches and we are left with bottom is equal to 1 inch again. We build and run. If you see the margins are different, top is 1 inch, left is 2 inches, right is 0.75 inches and bottom is 1 inch. So we saw how to set margins. We also saw how to set different margins for top, bottom, left and right. Now let's come to a two-sided document. Have you observed margins of a book? Well if you look closely, many books have different left and right margins depending on the odd and even page. This is true for all two-sided documents like a book. The margins are denoted as inner and outer. This takes care that no content gets cut while binding. So if you see on the even page, the inner margin is the right margin which is more and on the odd page the left margin is the inner margin. Inner margin is usually greater than the outer margin. Now let's see a demo. We change this to book class because it is a two-sided document. We add a chapter, say overview, there you go, A4 and instead of top, left, right and bottom we write inner is equal to 2 inch and outer is equal to 1 inch, build and run. You see the inner margin for the odd page number is 2 inches and for the even page number is 2 inches over here. So odd and even. So in this session we learnt to include a geometry package, we learnt to set the margins and the paper size. Thank you. Have a nice day.