The table shows the number of vertices, edges, and faces for the tetrahedron and dodecahedron.

\begin{tabular}{|c|c|c|c|}
\hline
& Faces & Vertices & Edges \\
\hline
Tetrahedron & 4 & 4 & 6 \\
\hline
Cube & 6 & 8 & 12 \\
\hline
Dodecahedron & 12 & 20 & 30 \\
\hline
\end{tabular}

1. Complete the missing values for the cube. Then, make at least two observations about the number of faces, edges, and vertices in a Platonic solid.

2. There are some interesting relationships between the number of faces [tex]$(F)$[/tex], edges [tex]$(E)$[/tex], and vertices [tex]$(V)$[/tex] in all Platonic solids. For example, the number of edges is always greater than the number of faces, or [tex]$E \ \textgreater \ F$[/tex]. Another example: The number of edges is always less than the sum of the number of faces and the number of vertices, or [tex]$E \ \textless \ F + V$[/tex].



Answer :

Let's complete the table and then make observations about the relationships between the faces, edges, and vertices of Platonic solids.

1. Complete the Missing Values for the Cube:
[tex]\[ \begin{array}{|c|c|c|c|} \hline & \text{faces} & \text{vertices} & \text{edges} \\ \hline \text{tetrahedron} & 4 & 4 & 6 \\ \hline \text{cube} & 6 & 8 & 12 \\ \hline \text{dodecahedron} & 12 & 20 & 30 \\ \hline \end{array} \][/tex]

2. Observations about Platonic Solids:

- Observation 1: The number of edges ([tex]\(E\)[/tex]) is always greater than the number of faces ([tex]\(F\)[/tex]) for the cube.
[tex]\[ \text{For the cube: } E = 12, \; F = 6 \; \Rightarrow \; E > F \; \Rightarrow \; 12 > 6 \][/tex]
Therefore, [tex]\(E > F\)[/tex] holds true for the cube.

- Observation 2: The number of edges ([tex]\(E\)[/tex]) is always less than the sum of the number of faces and the number of vertices ([tex]\(F + V\)[/tex]) for the cube.
[tex]\[ \text{For the cube: } E = 12, \; F = 6, \; V = 8 \; \Rightarrow \; E < F + V \; \Rightarrow \; 12 < 6 + 8 \; \Rightarrow \; 12 < 14 \][/tex]
Therefore, [tex]\(E < F + V\)[/tex] holds true for the cube.

By examining the cube and the given observations, we can see consistent relationships between [tex]\(F\)[/tex], [tex]\(E\)[/tex], and [tex]\(V\)[/tex] for Platonic solids:
- The number of edges is always greater than the number of faces, [tex]\(E > F\)[/tex].
- The number of edges is always less than the sum of the number of faces and vertices, [tex]\(E < F + V\)[/tex].

These relationships are fundamental properties of Platonic solids.