1. **State the problem:** We need to find the volume of a triangular prism with a triangular base of base length 7 m and height 4 m, and the prism length (depth) is 8 m. 2. **Formula for volume of a triangular prism:** $$\text{Volume} = \text{Area of triangular base} \times \text{length}$$ 3. **Calculate the area of the triangular base:** The area of a triangle is given by: $$\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}$$ Substitute the values: $$\text{Area} = \frac{1}{2} \times 7 \times 4 = \frac{1}{2} \times 28 = 14$$ 4. **Calculate the volume:** Multiply the area of the base by the length of the prism: $$\text{Volume} = 14 \times 8 = 112$$ 5. **Final answer:** The volume of the triangular prism is **112 cubic meters**.