To find the length of side \( DR \) in triangle \( RDP \), we can apply the Pythagorean theorem if triangle \( RDP \) is a right triangle.
We have:
- \( RP = 24 \)
- \( DP = 30 \)
Assuming \( DR \) is the unknown side \( x \), and applying the Pythagorean theorem:
\[ RP^2 + DR^2 = DP^2 \]
Substituting the known values:
\[ 24^2 + DR^2 = 30^2 \]
Calculating the squares:
\[ 576 + DR^2 = 900 \]
Now, isolate \( DR^2 \):
\[ DR^2 = 900 - 576 \]
\[ DR^2 = 324 \]
Now take the square root to find \( DR \):
\[ DR = \sqrt{324} = 18 \]
So, the value of \( DR \) is \( \boxed{18} \).