1. **State the problem:** We need to find the perimeter of square EFGH with vertices E(8, 10), F(-6, 10), G(-6, -4), and H(8, -4). 2. **Recall the perimeter formula for a square:** $$\text{Perimeter} = 4 \times \text{side length}$$ 3. **Find the side length:** Since EF and GH are horizontal sides, calculate the distance between E and F: $$\text{side length} = |x_E - x_F| = |8 - (-6)| = 8 + 6 = 14$$ 4. **Verify the vertical side length:** Check distance between F and G: $$|y_F - y_G| = |10 - (-4)| = 10 + 4 = 14$$ Since both horizontal and vertical sides are equal, the figure is a square with side length 14. 5. **Calculate the perimeter:** $$\text{Perimeter} = 4 \times 14 = 56$$ **Final answer:** The perimeter of square EFGH is 56.