1. • The cross section is the same all along its length
From last lesson:
A solid object with two identical ends and flat sides: • The sides are rectangles (or parallelograms)
• The cross section is the same all along its length
Cuboid
Triangular prism
Pentagonal prism

2. The Volume of a Prism How would you find the volume of the cuboid?
How could you alter this to find the volume of the triangular prism?
What about the pentagonal prism?
Cuboid
Triangular prism
Pentagonal prism

3. The Volume of a Prism
Volume of a prism = area of cross-section x height*
*height = distance between two ends
Cuboid
Triangular prism
Pentagonal prism

4. Is a cylinder a prism? A prism is…
A solid object with two identical ends and flat sides: • The sides are rectangles (or parallelograms)
• The cross section is the same all along its length

5. Is a cylinder a prism?
Although it is technically not a prism, you can find the volume in the same way.
The cross-section is a circle. How do you find the area of a circle?

6. Volume of a prism = area of cross-section x height*
*height = distance between two ends
10cm
18cm2

7. Volume of a prism = area of cross-section x height*
*height = distance between two ends
20cm
5cm
8cm

8. Volume of a prism = area of cross-section x height*
*height = distance between two ends
10cm
6cm
5cm

9. Find the volume of these triangular prisms

10. Challenge questions 20 cm 16 cm 12 cm 20 cm a b volume = 1200 cm3
what is a?
volume = 960 cm3
what is b?

11. Find the volume of these trapezoidal prisms.
(Can’t remember the area of a trapezium? See next slide)

12. a h b

13. Find the volume of these prisms and cylinders

14. Challenge questions