From the graph shown in the image:

1. Vertex set $V$: The vertices of the graph are labeled as $a$, $b$, $c$, and $d$. Therefore: $V = \{a, b, c, d\}$

2. Edge set $E$: The edges connect the following pairs of vertices:

   • $\{a, d\}$
   • $\{b, d\}$
   • $\{c, d\}$

   Thus, the edge set is: $E = \{\{a, d\}, \{b, d\}, \{c, d\}\}$

Let me know if you'd like further explanation or help with anything else! Here are related questions to deepen understanding:

1. How would the edge set $E$ change if an additional edge was added between $a$ and $b$?
2. Can you classify this graph as directed or undirected based on its edges?
3. How would the graph be represented using an adjacency matrix?
4. How can this graph be converted into a weighted graph?
5. What is the degree of vertex $d$ in this graph?

Tip: When defining edges in an undirected graph, ensure that each pair of vertices is represented as a set (e.g., $\{a, b\}$) rather than an ordered pair.