To find the length of the rectangular patio, you can use the formula for the area of a rectangle, which is:
\[ \text{Area} = \text{Length} \times \text{Width} \]
Given that the area is 72 m² and the width is 8 m, we can rearrange the formula to solve for the length:
\[ \text{Length} = \frac{\text{Area}}{\text{Width}} \]
Substituting in the given values:
\[ \text{Length} = \frac{72 \text{ m}^2}{8 \text{ m}} = 9 \text{ m} \]
Thus, the length of the patio is 9 meters.