To find half of lateral area is to find the whole lateral area divided by 2. The formula is 3. 14×20×20÷2=628(cm? ) Finally, the total area of the two parts is 3 14+628=942(cm? In this way, the surface area of a semi-cylinder is obtained.
The second step is to find the surface area of a cube, and the square on it is covered by a cylinder, so only the area of five squares is required, and the formula is 20×20×5=2000(cm? )
The third step is to add the surface areas of the two.
It's easier to find the volume. First find the volume of the whole cylinder, then divide it by 2 to get the volume of the semi-cylinder, plus the volume of the cube.