What geometric shape is generally used for stop signs?
A stop sign is generally an octagonal shape. This means it has eight sides and each of those sides is equal in length. With a stop sign, the angles are also equal between each of the sides.
The reason for the octagonal shape is that it is easy to see from a distance, both coming from the other direction and at night. It is also a shape that is not commonly used for other types of signs, so it is easily recognizable as a stop sign.