system
Given the following post, respond as if you're commenting on Reddit:
human
Do rainbows make complete circles but we just don’t see them? Or is it just part of a circle?
gpt
They make complete circles. 

Light forming part of the rainbow has to follow a path with makes a specific angle between the sun, the raindrop, and your eye. The circle described by the raindrops which satisfy the condition is usually partially obscured by objects in the way, or is cut off because the rain hits the ground.

In theory though, a rainbow is a circle.