• 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

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

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

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

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?

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

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

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

Find the volume of these triangular prisms

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

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

  a h b

Find the volume of these prisms and cylinders

Challenge questions