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Grade 8 Math — Surface area and volume

Find surface areas and volumes of cones, spheres and hemispheres.

Name: ________________________

  1. 1.A sphere has a radius of 14 inches. Take π = 22/7. What is its surface area, in square inches?

  2. 2.A hemisphere has a radius of 7 inches. Take π = 22/7. What is its total surface area, in square inches?

  3. 3.Which of these gives the volume of a sphere?

    • a) (1/3) × π × r × r × h
    • b) 4 × π × r × r
    • c) (4/3) × π × r × r × r
    • d) 2 × π × r × r

  4. 4.A cone and a cylinder have the same radius and the same height. How many coneloads of water would fill the cylinder?

  5. 5.A sphere has a radius of 21 inches. Take π = 22/7. What is its volume, in cubic inches?

  6. 6.A cone has a radius of 7 inches and a height of 24 inches. What is its slant height, in inches?

  7. 7.A cone has a radius of 7 inches and a slant height of 25 inches. Take π = 22/7. What is its curved surface area, in square inches?

  8. 8.A cone has a radius of 7 inches and a height of 12 inches. Take π = 22/7. What is its volume, in cubic inches?

Answer key — Grade 8 Math — Surface area and volume

  1. 1. 2464
  2. 2. 462
  3. 3. c) (4/3) × π × r × r × r
  4. 4. 3
  5. 5. 38808
  6. 6. 25
  7. 7. 550
  8. 8. 616