1. **State the problem:** Calculate the volume of a triangular prism with a triangular base of base length 12 cm and height 8 cm, and prism length 20 cm. 2. **Formula:** The volume $V$ of a triangular prism is given by: $$V = \text{Area of triangular base} \times \text{length of prism}$$ 3. **Calculate the area of the triangular base:** The area $A$ of a triangle is: $$A = \frac{1}{2} \times \text{base} \times \text{height}$$ Substitute the values: $$A = \frac{1}{2} \times 12 \times 8 = 6 \times 8 = 48$$ 4. **Calculate the volume:** $$V = 48 \times 20 = 960$$ 5. **Final answer:** The volume of the triangular prism is $960$.