Volume of a prism (including a polygonal prism or cylinder) = base area × height
📘 Example ① (Prism)
Find the volume of a square prism with a square base of side length 4 cm and a height of 6 cm.
Answer: Base area = 4×4 = 16 cm². Volume = 16×6 = 96 cm³
Find the volume of a square prism with a square base of side length 4 cm and a height of 6 cm.
Answer: Base area = 4×4 = 16 cm². Volume = 16×6 = 96 cm³
📘 Example ② (Cylinder)
Find the volume of a cylinder with a base radius of 3 cm and a height of 5 cm.
Answer: Base area = π×3² = 9π cm². Volume = 9π×5 = 45π cm³
Find the volume of a cylinder with a base radius of 3 cm and a height of 5 cm.
Answer: Base area = π×3² = 9π cm². Volume = 9π×5 = 45π cm³
💡 Key Point
- Volume of a prism = base area × height (the same formula applies to polygonal prisms and cylinders)
Practice Problems
- Find the volume of a cylinder with a base radius of 5 cm and a height of 4 cm (leave π as it is).
Answer and Explanation
- Answer: 100π cm³. Base area=25π. Volume=25π×4=100π.