PPMCC Posting Box

Problem:

Can we design 6 prisms and a cylinder which all have the same height and volume?

  • These 3D shapes will create a pleasing start to a posting box child's toy.
  • We know the volume of a prism and a cylinder is area of the base multiplied by the height.
  • If we design the bases to have the same area, then their volume will all be the same.

Plan:

  1. Use the 1cm grid paper to design the following shapes with an area of 9 square centimeters:
    • Square
    • Rectangle
    • Triangle
    • Parallelogram
    • Trapezium
    • Compound shape (two rectangles).
  2. Calculate the radius of a circle with the same area of 9 square centimeters.
  3. Calculate the perimeter of each of the shapes in order to explore the interesting relationship between area and perimeter.
  4. Decide the height of all the shapes, so explain the volume of all the 3D posting blocks.
  5. Tick of the skills from the Marking Tick Sheet.
    • Missing skills can be added. Convert the volume to mls.
    • Explain why you may need the volume in mls, perhaps a child could place all the shapes in a container of water and observe the water rise by this amount. Perhaps knowing the number of mls the shapes would displace would help you choose the correct size container for the child to use.
  6. Reflect on the learning.

Measure:

  • This will be clearly shown on your 1cm grid.
  • You can count squares vertically and horizontally, but must measure the diagonals.

Calculate:

All calculations must be clearly shown with:

  • Formula with name of the shape.
  • Label the variables eg base and height, radius.
  • Show the expression you would enter into your calculator.
  • Area, Perimeter and volume.

Conclude:

  • We have designed 6 prisms and a cylinder which all have the same height and volume.
  • Together their volume adds to...
  • This means the container they would be posted into should be as least...
  • Their surface areas are all different, because the perimeters of the base areas are all different.
  • What surprised me was....