1. **Problem Statement:** We have a prism with a regular decagonal cross-section. Each side of the decagon is 2 cm, and the height of the prism is 14 cm. We need to find: a) The area of each rectangular face. b) The total area of all the rectangular faces. 2. **Understanding the prism's faces:** The prism has 10 rectangular faces, one for each side of the decagon. Each rectangular face has one side equal to the side length of the decagon (2 cm) and the other side equal to the height of the prism (14 cm). 3. **Formula for the area of a rectangle:** $$\text{Area} = \text{length} \times \text{width}$$ 4. **Calculate the area of each rectangular face:** $$\text{Area of each face} = 2 \text{ cm} \times 14 \text{ cm} = 28 \text{ cm}^2$$ 5. **Calculate the total area of all rectangular faces:** Since there are 10 faces, $$\text{Total area} = 10 \times 28 \text{ cm}^2 = 280 \text{ cm}^2$$ **Final answers:** a) Area of each rectangular face = $28$ cm$^2$ b) Total area of the rectangular faces = $280$ cm$^2$