1. The problem is to draw a Venn diagram with 3 sets showing their union. 2. A Venn diagram with 3 sets consists of three overlapping circles, each representing a set. 3. The union of the three sets includes all elements that are in any of the sets. 4. To represent the union visually, we shade all areas covered by any of the three circles. 5. The formula for the union of three sets $A$, $B$, and $C$ is: $$A \cup B \cup C = A + B + C - (A \cap B) - (B \cap C) - (A \cap C) + (A \cap B \cap C)$$ 6. In the diagram, all three circles overlap partially, and the union is the entire area covered by all circles. 7. Below is the SVG diagram illustrating three overlapping circles with the union area highlighted.