volume of prisms and cylinders objective: be able to work out the volume of a prism and a cylinder
TRANSCRIPT
Volume of prisms and cylinders
Objective: Be able to work out the volume of a prism and a cylinder.
Volume of a prism
• the volume of a rectangular prism is:
length
width
height
Volume = length x width x height
Volume of a prism
• What is the volume of a rectangular prism with dimensions 10 cm, 8 cm and 5 cm.
Area of Base= 10 cm x 8 cm = 80 cm2
5 cm
10 cm8 cm
Volume of a cylinder
• Volume of a cylinder is the area of the cross-section times the height
Height h
Volume of cylinder = πr2h
Radius r
Find the volume of a cylinder with radius 10 cm and height 20 cm
Area of base = πr2= π x 102= π x 100= 100 π cm2
Height 20cm
Volume of cylinder = π r2h
= π x 100 x 20
= 2000 π cm3
Radius 10cm
Volume of prism = B x height
Find the volume of this prismSince the base is a triangle,
B=½ b h
B = ½ x 5 x 4
= 10 cm2
4cm
5cm
Volume of prism = 10 x 14
= 140 cm3
14cm
Volume of prism = B x height of the prism
Find the volume of this prism
The base is a parallelogram
B = 6 x 7
= 42 cm2
7cm
6cm
Volume of prism = 42 x 15
= 630 cm3
15cm
Volume of prism = B x height of the prism