1. **Stating the problem:** We have three 3D geometric shapes around a clock tower: a rectangular prism with dimensions 38 cm height and 15 cm width (depth unspecified), a triangular pyramid with base edge 18 cm and lateral edges 21 cm and 18.5 cm, and a cube with edges of 18 cm. 2. **Rectangular prism:** Given only height and width, volume requires depth. Assuming depth equals width (15 cm) for simplicity, $$V = \text{height} \times \text{width} \times \text{depth} = 38 \times 15 \times 15 = 8550\text{ cm}^3$$ 3. **Triangular pyramid:** To find volume: - Base area: base edge = 18 cm; assuming equilateral triangle, $$A = \frac{\sqrt{3}}{4} \times 18^2 = \frac{\sqrt{3}}{4} \times 324 = 81\sqrt{3} \approx 140.3 \text{ cm}^2$$ - Height of pyramid from lateral edges (21 cm and 18.5 cm) would require more info; without height, volume can't be precisely calculated. 4. **Cube:** Edge length 18 cm, $$V = 18^3 = 5832 \text{ cm}^3$$ **Final answers:** - Rectangular prism volume (assuming depth = 15 cm): $8550 \text{ cm}^3$ - Cube volume: $5832 \text{ cm}^3$ - Triangular pyramid volume: Insufficient data to calculate precisely.