Light doesn't travel in a shape, it travels in a straight line (unless it encounters something that bends it, like a lens or a mirror).

Here's why:

* Light is a wave: Light is an electromagnetic wave. Waves travel in a specific direction, like ripples on a pond.

* Straight lines are the shortest distance: In a vacuum, light travels in a straight line because that's the most efficient path. It takes the shortest distance between two points.

Think of a laser beam: It shoots out a straight beam of light. This is a good visual representation of how light travels in a straight line.