1. The problem asks to complete the table by measuring the side lengths of triangles △ABC and △DEF, then calculate the ratios $\frac{AB}{DE}$, $\frac{BC}{EF}$, and $\frac{AC}{DF}$. Finally, determine if these ratios are equal and complete the statement about triangle congruence. 2. The key formula here is the ratio of corresponding sides of two triangles: $$\text{Ratio} = \frac{\text{side of } \triangle ABC}{\text{corresponding side of } \triangle DEF}$$ 3. If the ratios $\frac{AB}{DE}$, $\frac{BC}{EF}$, and $\frac{AC}{DF}$ are all equal, then the triangles are similar by the Side-Side-Side (SSS) similarity criterion. 4. The statement to complete is: "If \textbf{two} angles of one triangle are congruent to \textbf{two} angles of another triangle, then they are \textbf{similar}." 5. Since the problem involves measuring and filling in data, the exact numeric values depend on the measurements taken. However, the process is: - Measure sides AB, BC, AC of △ABC. - Measure sides DE, EF, DF of △DEF. - Calculate each ratio: $\frac{AB}{DE}$, $\frac{BC}{EF}$, $\frac{AC}{DF}$. - Check if all three ratios are equal. 6. If all three ratios are equal, then $\frac{AB}{DE} = \frac{BC}{EF} = \frac{AC}{DF}$, confirming similarity by SSS. 7. If the ratios are not equal, the triangles are not similar by SSS. This completes the problem as requested.