Final answer:
The sign shaped like a pentagon is a stop sign. A stop sign is a traffic sign used to indicate that drivers must come to a complete stop before proceeding.
Step-by-step explanation:
The sign shaped like a pentagon is a stop sign. A stop sign is a traffic sign used to indicate that drivers must come to a complete stop before proceeding. It is usually red and white and has the word 'STOP' written on it. Stop signs are placed at intersections where it is important to control the flow of traffic and ensure safety.