In the UK, it would be a warning sign, thus it would be a Triangle.
The nouns in the sentence are: sign, drivers, rocks, and street.
A sign warned drivers of falling rocks along the street.
Look out for falling rocks. The area along the road is unstable and rocks could fall loose onto the roadway. The sign is warning that you should be vigilant for objects in the road.
bears, snakes, Falling rocks , Cliffs
An octagon would be the shape of a stop sign.Stop has 8 sides and so does the octagon.
The verb is "warned." It's the past tense of "to warn." But be advised that some signs do not have verbs at all: they just have fragments like "no passing" or "school zone." And as others on this page have noted, "falling" can be a verb, but in the sentence you asked about, it is not--it's an adjective that describes "rocks."
good
The shape with six edges is a called a hexagon. Examples of a hexagon would be a stop sign on the road.
that one sign, with that one shape to it... you know that tells you to do those one things
It is in the shape of a shield.
i would say peace sign if you could that a shape or a heart ♥ so pretty ♥♥♥♥♥
A regulation sign is a sign that gives you the regulation for something. These signs are always in white and black and rectangle in shape. An example is a speed limit sign.