Final answer:
The equilateral triangle shaped sign pointed down is a traffic sign and it falls under the subject of Social Studies. Specifically, it indicates that drivers and pedestrians should YIELD to other vehicles and pedestrians.
Step-by-step explanation:
The equilateral triangle shaped sign pointed down is a traffic sign and it falls under the subject of Social Studies. Specifically, it relates to the topic of traffic rules and regulations. In this case, the sign indicates that drivers and pedestrians should YIELD to other vehicles and pedestrians.