To rewrite the irrational square root of \( 72 \) as the product of an integer and another irrational square root, we first factor \( 72 \) into its prime factors:
\[ 72 = 2^3 \times 3^2 \]
Next, we can express \( \sqrt{72} \) as follows:
\[ \sqrt{72} = \sqrt{2^3 \times 3^2} \]
We can separate this into two parts:
\[ \sqrt{72} = \sqrt{2^2 \times 2^1 \times 3^2} \]
Using the property of square roots that states \( \sqrt{a \times b} = \sqrt{a} \times \sqrt{b} \), we can rewrite this as:
\[ \sqrt{72} = \sqrt{2^2} \times \sqrt{2^1} \times \sqrt{3^2} \]
Calculating the square roots of the perfect squares:
\[ \sqrt{2^2} = 2 \quad \text{and} \quad \sqrt{3^2} = 3 \]
Thus, we have:
\[ \sqrt{72} = 2 \times 3 \times \sqrt{2} = 6 \sqrt{2} \]
Therefore, the square root of \( 72 \) rewritten as the product of an integer and another irrational square root is:
\[ \sqrt{72} = 6 \sqrt{2} \]