Five witnesses (Including myself) were watching a meteor shower and saw three bright, blue-green lights go across the sky in 5 seconds

Four friends and I were out watching a meteor shower that night.  The first meteor shower I ever watched.  I had started counting meteors, which were appearing one at a time for a while.  The meteors went across the sky usually in a northwest direction.
We were all laying in the grass so we could get the best view of the sky without hurting our necks (And so that the nearby street lights would be less obstructive to our viewing of the sky).
One of my friends saw it first, pointed up at a group of three blueish green lights, whether they're part of one craft or separate craft, we're not sure.  They were in perfect equilateral triangle formation.
As soon as we saw the three lights, they accelerated at an impossible rate heading west, almost from horizon to horizon.  The three lights picked up speed as they went and had started to rotate before disappearing behind a large cloud.
The night was fairly calm, and there wasn't much wind.   We sat there for about 3 seconds after seeing the object, confirmed that the others saw it too, and then we all ran into the house terrified.  We had heard nothing from whatever craft flew over us.
Witness indicates that the date is approximate.  PD