For a project, Gabrielle made a model of an Egyptian pyramid. The square base has a side length measuring 10 inches. The pyramid is 12 inches tall.What is the surface area of the model?

Each triangular face has a slant height of 13 inches: the pyramid’s 12-inch height and half the 10-inch base side form a right triangle, so √(12² + 5²) = 13. The four triangles have a combined area of ½ × 40 × 13 = 260 square inches, where 40 inches is the base perimeter. Add the 100-square-inch base to get 360 square inches, so the answer is D, 360 square inches.

AI-written and checked against the verified answer.