Observed a single light not blinking with a Silhouette black that appeared to be in the shape of a Triangle

Took dogs out back and looked up at the sky and noticed a single light flying south of my house approximately 30k ft or about the height of airplanes. The single light did not blink and the UFO was swerving and make twirls in the air. As the UFO was flying you could see a black silhouette of what appeared to be a Triangle as the craft kept going the light faded out and could not see the craft at all. 20-30 seconds later an airplane appeared heading north from from possibly a mile or two from where the UFO disappeared, as if it was hiding from the plane. Please note as the UFO flew over there was no sound or engine noise from it but as soon as the plane flew over you could clearly hear its engines.