Final answer:
To calculate the volume of the wooden box, subtract the wood's thickness from each external dimension to get internal dimensions. Then, multiply the internal length, width, and height to find the volume, which is 4105.984 cm³.
Step-by-step explanation:
To find the volume of the wooden box with given external dimensions and wood thickness, we first need to calculate the internal dimensions by subtracting the thickness of the wood from the external dimensions. As the wood is 9 mm thick, which is 0.9 cm, we subtract this twice from each of the external dimensions (since the thickness is on both sides).
- Internal length: 21 cm - 0.9 cm - 0.9 cm = 19.2 cm
- Internal width: 18 cm - 0.9 cm - 0.9 cm = 16.2 cm
- Internal height: 15 cm - 0.9 cm - 0.9 cm = 13.2 cm
Next, the volume of the wooden box is calculated using the formula:
Volume = length × width × height,
Volume = 19.2 cm × 16.2 cm × 13.2 cm,
Volume = 4105.984 cm³.
Therefore, the volume of the wooden box is 4105.984 cm³.