Final answer:
Pentagon shaped signs are used to indicate a school zone in road traffic and to symbolize the military in military symbolism.
Step-by-step explanation:
Pentagon shaped signs are commonly used in road traffic to indicate a school zone. These signs are yellow in color and have the word 'School' written on them. They are placed near schools to alert drivers to slow down and be cautious of children crossing the road.
Another use of pentagon shaped signs is in military symbolism. The Pentagon building in Washington, D.C., which is the headquarters of the United States Department of Defense, is shaped like a pentagon. The pentagon symbolizes the strength and unity of the military forces.