Subtitles of the Movie

So let's have a look at the Coordinate System. I have a circle there with a center of 50, 50 and a diameter of 40. So let's have a look at that from a Coordinate Viewpoint. Now one thing you can use is a very useful command, we will cover it later in the course as well. but if you go to your Tools Menu here, your Tab on the ribbon you'll notice that the Panels will change and we have an Inquiry Panel here. This icon here is ID Point. Now when I click on that and come into the drawing area, the dynamic input is prompting me to specify a point. Now if I go and hover over the circle I've got Object Snaps switched on so the center of the circle will highlight because its an Object Snap, when I left click on it, it tells me that X and Y or 50 and 50 as per what I typed in. So now let's go back to the Home Tab because I want the Draw Panel and what I want to do now is I want to draw a line. So I'm going to type in using Absolute Coordinates. Now Absolute Coordinates are relative to the naught, naught down here on the X and Y. So if I now click on my Line Command here and come into the drawing area AutoCAD is prompting me to specify the first point of the line. Now it would also do that on the Command Line. If you look at the Command Line it's also prompting me to specify the first point. But I'm using dynamic input so my primary input method is on the screen near the cross hair, that's what dynamic input is all about. So I type in the first box there 50 where its highlighted in blue. If I now press the Comma Key on the keyboard that will take me to the Y Box, the Y Coordinate box if I type in 50 there and press Enter my line starts from the center of my circle, because they both share that common point, that 50, 50 and its an Absolute Coordinate from 00. So 50 along the X axis, 50 up the Y axis in a positive direction. Notice if you look at where 00 is and look at where the start of that line is and the center of the circle is you can see there exactly why that is 50, 50. Now what I'm going to do now is I'm going to drag my line along the 0 degree line. See the dotted line that appears and the Polar shows up on the dynamic input? Well what I'm doing now is I'm going to type in what they call Direct Distance Entry, I'm moving in a direction. Now the Polar Tracking, the Polar Button down on the status bar has picked the 0 there, AutoCAD always goes to the right horizontally at 0 degrees by default. Now I can type in a direct distance entry in that box where its highlight in blue. At the moment is shows 48.396. So if I type in 100 it will now draw me a line 100 long going from the center of the circle to the right at 0 degrees. If I press Enter now there's my line 100 long and AutoCAD is now prompting me for the next segment of my line.