Tawfik Shehata shares a trick using AutoCAD grips to help you verify drawing accuracy.
"Sometimes two lines meeting at one point will not let you join them or use them as hatch boundaries. This usually happens because they don’t really meet at the same point as they seem to; either due to a difference in elevation (z value), or because there is a little gap between their end points — one so minor that you’ll need to perform lots of zoom-in and regen to spot it.
"A quick method to check if these objects meet at exactly the same point or not is to select them to show their grips, then click on the grip where the objects seem to meet and try to drag in any direction. Only grips located at the exact same coordinates will move together when picked and dragged. When you drag, you'll be able to see whether all the objects will stretch/move with your cursor, or some of them will remain as is, which means in this case that they don’t meet at the exact point with the ones responding to the cursor.
"Using this method, you can also quickly check if a text or block is inserted exactly at a circle center point."
Notes from Cadalyst tip reviewer Brian Benton: Grip edits are a very useful thing. You can quickly edit your drawing objects without ever starting a command. You can stretch the endpoint of a line, or arc. You can move an object. You can edit multiple objects at one time using grips.
If two lines end at the same x,y,z coordinates, they will share a grip. If both objects are selected, then what you do to one of those grips will also be done to the other. If they aren’t in the same x,y,z location, then they don’t share grips. This is a very easy trick to check this type of thing.