White triangular formation saw in the early morning Michigan sky.

I work as a paramedic for a local ambulance service. So I want to first state that I don’t exactly know what I saw. Second, I want be the first to admit both the gentleman I work with and I were fatigued as we work 24 hour shifts. The day in particular had been very busy and we had not the opportunity to sleep at our base. Both of us had been awake approximately 19 hours.
My partner and I were dispatched to a non emergent 911 call at approximately 0130. As we traveled northbound on Dehmel near the cross street of Canada, I notices three triangular shaped objects in a triangle formation to the northeast. These objects remained in what appeared to be an overall stationary triangle formation with the individual objects moving away from each other and then back towards each other in an almost rhythmic way. I really don’t know how to explain the color of the objects. They were a bright white color but I found them odd because the “light” of the objects didn’t appear to radiate from the object as a light source would naturally. These objects were simply just a triangle of bright white. I had no obvious frame of reference to judge the size of the objects but they appeared larger than backdrop of stars yet smaller than the moon. I pointed the object to my partner whom was writing a patient care report. He brushed it off as nothing and continued to type his report. As we continued northward, the object suddenly flew southward. As we entered the residence (I have to omit the details of this location due to HIPAA), we noticed the objects to the south. Low against the horizon but still in a triangular formation. When we left the residence, the objects were gone.
After the conclusion of the call my partner brought up the event but again brushing it off by saying that we must have been very exhausted if we were seeing things in the sky. We both laughed about it and returned to our base. After a few days, I can’t shake whatever it is I saw. I just don’t know what it was.