Changing dimensions of an object?

[Anonymous]

Sorry if it is a simple question but i am newbie and i want to ask if anyone can tell me how to change dimensions of an object?

For example: I draw a wall and then i want to make it to be 3000 mm. How to edit that? Is there a tool for putting a dimension on an object?

[Laszlo Nagy]

When you click a Wall and it is selected, selection hotspots appear the both ends of the Wall. Click one of them and you can stretch that end of the Wall.
If you want to see dimensions of elements, check the Help File for Coordinate Box and Tracker.
There are also free training materials available. You should do those and you will learn all the basics of the program:

http://www.graphisoft.com/products/archicad/training_guides/