external image Professors_cube.jpg

Constructing Prisms and Finding Volume
Constructing Prisms
  • Open "Google SketchUp" on your laptop.
  • Delete the man by clicking on him and pressing "Delete"
  • Construct a rectangular prism:
Select the "Square" tool
Draw the rectangle from the middle of the axes out to the right.
Chose the tool with the red arrow pointing up out of a box.
Click on your rectangle and drag it up to create a prism.
prisms2.jpg
Use the same tool to move the front face in and out. Notice the face is the same shape all the way through.

This shape is the CROSS SECTION.
  • Construct a triangular prism in a simmilar way. (Use the pencil to draw the triangle)
prisms1.jpg
The CROSS SECTION of a triangular prism is a:


Volume of a Prism

The volume of a prism is found by:

Written as a formula:
V=

So to find the volume of prisms, we need to find the area of the cross section by using formulas. Remember these are:
external image common-geometry-formulas.jpg

Surface area of prisms and Converting units
Surface Area of Prisms

A Prism is a solid shape. It has the same shape all the way through. The prism is named by its end face. Here are some examples:

external image rectangular_prism.jpg&h=78&w=78&usg=__JhdEpdVaysS38nEebGCJYhQ1JRU=Rectangular prism (has the shape of a rectangle all the way through)
external image IntegralBugTentF06.jpgTriangular prism (has the shape of a triangle all the way along the tent)

· Write a definition for the surface area of a prism (how would you work it out?)



· Open a new window and go to the following site:

http://www.shodor.org/interactivate/activities/SurfaceAreaAndVolume/

· Drag the WIDTH slider to the end. Leave the other ones.
· Use the mouse to spin the shape around. How many sides does this shape have?


· Write down the area of each face:

1: units2
2: units2
3: units2
4: units2
5: units2
6: units2
Find the SURFACE AREA by adding the areas of each face: units2
Check your answer.

· Do the same for a triangular prism.

Number of sides:
Area of each face:






SURFACE AREA=


Revision: Converting Units:

· Use Google to search for the following words (Wikipedia definitions are fine). Write down the meanings:

Kilo:
Mili:
Centi:

· Use the above information to complete the following

1m = cm

1cm = mm

1cm3 = mm3

1L = mL= 1000cm3

1000L = 1 kL = 1m3

cm3
L
1000

5400

60000


L
kL
1000

2500

60000


· Use Google to find the volume of the following. Comment on the units used. E.g. If the volume was 378000L, is this litres the best unit to use? kL would be better: 378kL

Olympic sized pool:


Average daily Household water usage in NSW (use the link):
http://www.abs.gov.au/ausstats/abs@.NSF/2f762f95845417aeca25706c00834efa/ce3d55f44b3d49f6ca25703b0080ccd0!OpenDocument

Volume of Cylinders and Composite Solids
  • Construct a cylinder using Google SketchUp.
cylinder1.jpg
  • Write down a formula for the volume of a cylinder. (Hint: Use the formula for area of a circle)

  • Make a simple house using Google SketchUp. The house should consist of a rectangular prism and a triangular prism.
house.jpg
  • Name the two Prisms that make up this house
1.
2.
  • Explain how you would find the volume of the house.