3D Shapes

3D Shapes

1. Volume

   • Cylinder
     • V= πr^2 x H
     • V= (Pi x radius) squared x Height
   • Cuboid
     • V= L x W x H
     • Volume= Length x Width x Height
   • Prism
     • V= Area of cross-section x Length
     • V= AC x L
   • REMEMBER
     • Give in cubic units
       • x^3
   • Cube
     • L x 3

2. Surface Area

   • Formulas
     • Cuboid
       • 2hl x 2 hw x lw
     • Cylinder
       • 2πrh x 2πr^2
   • It is a sum of all the faces
   • x^2

3. Converting Volume Units

   • Example
     • A cube has the length of 1m. This is the same as a length of 100cm. Therefore, 1m^3 = 1000000cm^3
   • 1m^3 = 1000000cm^3
     • Why?
       • 100 x 100 x 100cm
       • 1 x 1 x 1m
       • =

4. Volumes of Enlargements

   • Example
     • If a cube of length 1cm is enlarged by a scale factor of 2, what is the volume of the new shape?
       • Before = 1^3 Now= 2^3
         • 8

5. Properties of 3D Shapes

   • Cube/Cuboid
     • 6 faces
     • 12 edges
     • 8 edges
   • Tringular Prism
     • 2 triangular faces
     • 3 rectangular faces
   • Cylinder
     • 2 circular faces
     • 1 curved face