Step 1: Understanding the formula.
For a fault, the dip separation \( S \) can be calculated as:
\[
S = \sqrt{\text{Throw}^2 + \text{Heave}^2}
\]
Step 2: Substitute the given values.
Throw = 4 m, Heave = 3 m. Therefore:
\[
S = \sqrt{(4)^2 + (3)^2} = \sqrt{16 + 9} = \sqrt{25} = 5
\]
Final Answer:
\[
\boxed{5}
\]