Red lights in the sky

At approximately 9:45 pm a red dot lit up the sky. It looked like a tip of a signal flare without the trail leading up.
A few minutes later, there were two red lights blinking in sequence one after another, drawing out a triangle. This continued for a few minutes with the dots getting closer and further apart, drawing out a bigger triangle.
In the final stages there was a total of 5 red lights arranged in an incomplete triangle burning brightly in the sky, remains still. After about 5-15 seconds, the lights disappeared completely.