Step 1: Use Euler's formula for planar graphs.
For a connected planar graph, Euler's formula is given by:
\[
V - E + F = 2
\]
where \( V \) is the number of vertices, \( E \) is the number of edges, and \( F \) is the number of faces.
Step 2: Substitute the given values.
Here, \( V = 8 \) and \( F = 5 \). Substituting into Euler's formula:
\[
8 - E + 5 = 2
\]
Step 3: Solve for \( E \).
\[
13 - E = 2
E = 11
\]
Step 4: Final result.
Thus, the number of edges in the graph is \( 11 \).
% Final Answer
Final Answer: \[ \boxed{11} \]
In the diagram, the lines QR and ST are parallel to each other. The shortest distance between these two lines is half the shortest distance between the point P and the line QR. What is the ratio of the area of the triangle PST to the area of the trapezium SQRT?
Note: The figure shown is representative
