1. **State the problem:** Calculate the volume of a triangular prism with a triangular base of base length 11 cm and height 5 cm, and prism length (depth) 9 cm. 2. **Formula for volume of a triangular prism:** $$\text{Volume} = \text{Area of triangular base} \times \text{length of prism}$$ 3. **Calculate the area of the triangular base:** The area of a triangle is given by: $$\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}$$ Here, base = 11 cm and height = 5 cm. 4. **Calculate the area:** $$\text{Area} = \frac{1}{2} \times 11 \times 5 = \frac{1}{2} \times 55 = 27.5 \text{ cm}^2$$ 5. **Calculate the volume:** Multiply the area of the base by the length of the prism (9 cm): $$\text{Volume} = 27.5 \times 9 = 247.5 \text{ cm}^3$$ 6. **Final answer:** The volume of the triangular prism is **247.5 cm³**. Note: The 6 cm segment inside the triangle is not needed for volume calculation since the height of the triangle is given as 5 cm perpendicular to the base.