To measure for an out of square corner you will need to know what is referred to as the 3-4-5. Measure 3' down one wall, 4' down the other wall. When you connect the two points, a square miter will measure 5' exactly. When the measurement is something other than 60" your corner is out of square and this is the measurement we need to cut your out of square corner at.
The following diagrams show the Shad's way of cutting clip corners. When a drawing specifies 3" or 6"clip corner. The FACE of the clip is 3" or 6" unless otherwise noted. When a clip is done this way, add the same measurement of the clip for your overhang. ( 3" Clip = 3" Overhang, 6' Clip = 6" Overhang)
Custom Clips Corners can be measured as shown, this would be a 3" custom clip. You must specify on your order to cut the clip this way. Always add 1" more than the size of the clip corner. (you would add 4" of overhang for this 3" custom clip)