1. **Problem:** Draw $A$ or $B$ as a diagram. 2. **Formula used:** In set notation, “or” means the union, written as $A\cup B$. 3. **Important rule:** The union includes every element that is in $A$, in $B$, or in both sets. 4. **Example sets:** Let $A=\{1,2,3\}$ and $B=\{3,4,5\}$. 5. **Work:** $$A\cup B=\{1,2,3,4,5\}$$ The number $3$ is in both sets, but it appears only once in the union. 6. **Diagram meaning:** The picture should show two overlapping circles labeled $A$ and $B$, with the overlap representing the common part and the whole shaded union representing $A\cup B$. 7. **Final answer:** The union is $A\cup B=\{1,2,3,4,5\}$, and the diagram should show both sets together with the overlap included.