Answer: \(\triangle APQ \sim \triangle ARS\) (SAS test), so \(\frac{PQ}{RS} = \frac{1}{5}\), i.e. SR = 5PQ.
From the given data,
\[AR = 5AP \Rightarrow \frac{AP}{AR} = \frac{1}{5}\]
\[AS = 5AQ \Rightarrow \frac{AQ}{AS} = \frac{1}{5}\]
In \(\triangle APQ\) and \(\triangle ARS\):
- \(\frac{AP}{AR} = \frac{AQ}{AS} = \frac{1}{5}\)
- \(\angle PAQ \cong \angle RAS\) (vertically opposite angles)
\(\therefore \triangle APQ \sim \triangle ARS\) (SAS test of similarity).
Corresponding sides of similar triangles are in proportion, so
\[\frac{PQ}{RS} = \frac{AP}{AR} = \frac{1}{5}\]
\(\therefore\) SR = 5PQ. Hence proved.