1. **State the problem:** Simplify the fraction $$\frac{(3p)^2}{72pr}$$. 2. **Apply the exponent:** Recall that $ (ab)^2 = a^2 b^2 $. So, $$ (3p)^2 = 3^2 \times p^2 = 9p^2 $$. 3. **Rewrite the fraction:** $$ \frac{9p^2}{72pr} $$. 4. **Factor numerator and denominator:** - Numerator: $9p^2 = 9 \times p \times p$ - Denominator: $72pr = 72 \times p \times r$ 5. **Simplify common factors:** - Both numerator and denominator have a factor of $9$ and $p$. - Divide numerator and denominator by $9p$: $$ \frac{9p^2}{72pr} = \frac{9p \times p}{9p \times 8r} = \frac{p}{8r} $$. 6. **Final simplified form:** $$ \boxed{\frac{p}{8r}} $$. This is the simplest form of the given fraction.