To find the scale factor used by Leo to enlarge the jewelry from its original size to the size in the photograph, we can use the formula for scale factor:
\[ \text{Scale Factor} = \frac{\text{New Size}}{\text{Original Size}} \]
In this case, the original size of each side of the pentagon is 3 centimeters, and the new size is 8 centimeters.
Plugging in the values:
\[ \text{Scale Factor} = \frac{8 \text{ cm}}{3 \text{ cm}} = \frac{8}{3} \]
Converting \(\frac{8}{3}\) to a mixed number gives us:
\[ \frac{8}{3} = 2 \frac{2}{3} \]
Thus, the scale factor that Leo used to create the photograph from the original is:
2 2/3