1. **State the problem:** We need to determine which triangles are similar to triangle ABC with sides 5, 7, and 8. 2. **Recall the similarity rule for triangles:** Two triangles are similar if their corresponding sides are in proportion, i.e., the ratios of their corresponding sides are equal. 3. **Check triangle DEF:** Sides are 10, 10, 10 (equilateral). - Ratios with ABC sides: \(\frac{10}{5} = 2\), \(\frac{10}{7} \approx 1.43\), \(\frac{10}{8} = 1.25\). - Since the ratios are not equal, triangle DEF is not similar to ABC. 4. **Check triangle GHI:** Sides are 6, 9, 10. - Sort sides of ABC and GHI for comparison: - ABC sorted: 5, 7, 8 - GHI sorted: 6, 9, 10 - Ratios: - \(\frac{6}{5} = 1.2\) - \(\frac{9}{7} \approx 1.29\) - \(\frac{10}{8} = 1.25\) - Ratios are not equal, so triangle GHI is not similar to ABC. 5. **Conclusion:** Neither triangle DEF nor triangle GHI is similar to triangle ABC. **Final answer:** (D) Neither