i not sure if this is the correct section for this but here is a litle toturial about AUTOCAD 2010.
Ok this is a toturial i going to explain how to do some Parametric Constraints on AUTOCAD :
In this part u must do start with 4 lines
here u must select that tool over there saying coincident after u alredy did the 4 lines
next step is by selecting that tool go now to the rectangle and select 2 lines 1 horizontal and other in vertical line u will now see something like a red target and after u have done 2 lines somethnig will hapend and u will see now a corner.
in this part you have now the rectangle with all corners after that u must go for other comand and tool i will explain what do next
ok in this part u must choose the perpendicular tool on the top left corner over there and select to use on rectangle
next part u have to select with the perpendicular tool 2 lines as it show in the picture.
in this picture u now must use the comand and parallel tool like image shows
Here u can see that now i have used parallel tool in all lines wish and as u can see now it is a perfect rectangle done this time and almost done with the thing.
ok now you can drag by selecting a point to make the rectangle more correct and more exact at a certain line in the drawing image.
the final part and conlusion is that u need to go now first align tool ther wher it shows some lock in yelow and select 2 corners on the uper side on the horizontal then u must do it again select the aligned tool lock and select the botom left corner and the uper left corner cause u must select that line on the vertical side, doing this will give u some values and numbers.
Now the last thing is go at parameters manager to see window pops up there and u wil see some things there now showing up,u can change the values by clicking on D1 AND D2.
you may notice that now your rectangle can change with this values giving also some difrent size depending of the valuea and number you want to add or put in that box.
Well its not much but this is just a litle something i know about using AUTOCAD 2010 and i also know more things,but for now i let u guys with this small toturial and to let u know a litle how autocad looks like guys.
hope u guys like my toturial soon i show up more if u guys want to learn some more autocad things cause this version we can also do some 3 D MODELING wish is very interesting and i alredy am using .
other thing also is that in autocad 2009 this 3 d thing its not possible but i also got 2009 version and with 2010 autocad this is a beter version and u can work more faster then the other and it got more new features.