在韦恩图上，给表示 $A' \cup B$ 的区域涂上阴影。 用集合符号描述阴影区域。

1. Identify the regions included in $A' \cup B$ and shade them

$A'$ is the region outside $A$.

$A' \cup B$ means all points that are in $A'$ or in $B$.

So shade:

• all regions outside circle $A$,
• the whole of circle $B$, including $A \cap B$.

The only region not shaded is $A \cap B'$, the part inside $A$ but outside $B$.

1. Describe the shaded annular region in set notation

The shaded region is inside $A$ and outside $B$.

Hence the region is
$A \cap B'$.