Group tarps

Greyson, the beauty of any size of these tarps is their flexibility. I've found that the 10' length is adequate for head-to-toe coverage with guys that are 6 foot and taller.

Here's an example lean-to pitch that provided room accommodations for 3. We had a light rain that night.

This tarp is a 10' x 12' Campmor (Equinox) silnylon tarp. There was easily 8' of covered length in this configuration. An a-frame pitch can provide better weather coverage. Here's the same tarp in an a-frame pitch.

Let a be the width of the tarp, b the height of the pitch, and c be how far the ends of the tarp are to be from the ground. Then the width of the coverage area is
2*squareroot( (a^2)/4 – (b-c)^2 )

So, if it is pitched at a height of 4 ft., 1 ft. off the ground the 10 ft width would have 8 ft. of coverage. If the ends are all the way to the ground it becomes 6 ft., etc.

Thanks guys, both of your responses are very helpful.
Anybody have any subjective experience in using large group tarps instead of two two person, or four one person tarps?
Preferences?
Not so obvious pros and cons?

Any experiences would be appreciated.