A closed container is a frustum with bottom radius 10 cm, top radius 4 cm and height 8 cm…

Step 1. The slant height. $l = \sqrt{8^2 + (10 - 4)^2}\ \text{cm} = 10\ \text{cm}$.

Step 2. The curved surface. $\pi(10 + 4)\ \text{cm} \times 10\ \text{cm} = 140\pi\ \text{cm}^2$.

Step 3. The two ends. $\pi \times 100\ \text{cm}^2 + \pi \times 16\ \text{cm}^2 = 116\pi\ \text{cm}^2$.

Step 4. The total. $140\pi + 116\pi = 256\pi\ \text{cm}^2 = 804.2\ \text{cm}^2$.

Step 5. The volume. $\dfrac{\pi \times 8\ \text{cm}}{3}(100 + 40 + 16)\ \text{cm}^2 = \dfrac{8 \times 156}{3}\pi\ \text{cm}^3 = 416\pi\ \text{cm}^3 = 1306.9\ \text{cm}^3$.