Math 9 · Unit 14: Volume, surface area and symmetry · Cambridge Lower Secondary Maths Stage 9

Questions

1. 1. The diagram shows some 3D shapes. Artur has drawn a plane of symmetry on each shape. He has drawn only two of the planes of symmetry correctly. Tick the 2 planes of symmetry he has drawn correctly.

   Tick all the right answers.

   • ☐ a
   • ☐ b
   • ☐ c
   • ☐ d
   Check

2. 2. Here are six prisms, A to F. Tick the 2 prisms that have one plane of symmetry.

   Tick all the right answers.

   • ☐ A
   • ☐ B
   • ☐ C
   • ☐ D
   • ☐ E
   • ☐ F
   Check

3. 3. Here are six prisms, A to F. Tick the 2 prisms that have two planes of symmetry.

   Tick all the right answers.

   • ☐ A
   • ☐ B
   • ☐ C
   • ☐ D
   • ☐ E
   • ☐ F
   Check

4. 4. Here are six prisms, A to F. Which prism has three planes of symmetry?

   • A
   • B
   • D
   • C
   Check

5. 5. A cuboid measures 1 cm by 3 cm by 3 cm. How many planes of symmetry does it have?

   • 3
   • 5
   • 9
   • 4
   Check

6. 6. The diagram shows a hexagonal prism. Its hexagon is not regular. How many planes of symmetry does it have?

   • 3
   • 1
   • 6
   • 7
   Check

7. 7. Regular polygons are each made into a pyramid: triangle, square, pentagon, hexagon and octagon. Which choice correctly completes the table?

   • Lines 3, 4, 5, 6, 8; planes 4, 5, 6, 7, 9
   • Lines 3, 4, 5, 6, 8; planes 6, 8, 10, 12, 16
   • Lines 3, 4, 5, 6, 8; planes 1, 1, 1, 1, 1
   • Lines 3, 4, 5, 6, 8; planes 3, 4, 5, 6, 8
   Check

8. 8. What is the connection between the number of lines of symmetry of a regular 2D polygon and the number of planes of symmetry of its matching 3D pyramid?

   • The pyramid has one more.
   • They are the same number.
   • The pyramid has twice as many.
   • The pyramid has none.
   Check

9. 9. A decagon has 10 sides and a dodecagon has 12 sides. Use the connection to write the number of planes of symmetry of a regular decagonal pyramid and of a regular dodecagonal pyramid.

   • 11 and 13
   • 10 and 12
   • 20 and 24
   • 5 and 6
   Check

10. 10. This is an isometric drawing of half of a three-dimensional shape. The shaded face is on the plane of symmetry. How many other planes of symmetry does the completed shape have?

    • 3
    • 2
    • 1
    • 0
    Check

11. 11. This is an isometric drawing of half a shape. The shaded face is on the plane of symmetry. What is the name of the whole shape?

    • triangular prism
    • hexagonal prism
    • cube
    • square-based pyramid
    Check

12. 12. This is an isometric drawing of half a shape. The shaded face is on the plane of symmetry. How many planes of symmetry does the whole shape have?

    • 12
    • 3
    • 9
    • 6
    Check