Q1. What is the curved surface area of a cylinder with radius 5 cm and height 8 cm?
Q2. A cone has radius 6 cm and perpendicular height 8 cm. What is its slant height?
Q3. What is the surface area of a sphere with radius 3 cm?
Q4. An open cylinder (no top) has radius 4 cm and height 9 cm. What is its total surface area?
Q5. A cylinder and a sphere have the same radius r. The cylinder has height 2r. What is the ratio of the cylinder's total surface area to the sphere's surface area?
Q6. Find the total surface area of a closed cylinder with radius 7 cm and height 12 cm. (2 marks)
Q7. A cone has radius 5 cm and perpendicular height 12 cm. Find its total surface area. (3 marks)
Q8. Explain why a sphere has the smallest surface area for a given volume of any 3D shape, and give two real-world examples where this property is useful. (3 marks)