Printable Worksheets
Print or save as PDF — or build a custom worksheet from any module's questions.
Surface Area and Volume of Prisms and Cylinders
A cube has side 4 cm. What is its total surface area? What about a cylinder with radius 3 cm and height 5 cm?
Learning Intentions
Know
- Prism cross-section
- Lateral surface area
- Total surface area of cylinder
Understand
- Why a prism's volume depends on its cross-section
- How unfolding a cylinder reveals its net
Can Do
- Find surface area of rectangular prisms
- Find surface area of cylinders
- Decompose composite solids
Prisms
A prism is a solid with a constant cross-section. Its volume is:
$V = ext{Area of cross-section} imes ext{height (or length)}$
The surface area is the sum of all face areas.
Rectangular prism: $SA = 2(lw + lh + wh)$
Cylinders
A cylinder has two circular bases and a curved side.
$V = pi r^2 h$
$SA = 2pi r^2 + 2pi r h$
The term $2pi r h$ is the lateral (curved) surface area.
Imagine unrolling the cylinder: the curved surface becomes a rectangle with dimensions $2pi r imes h$.
Nets
A net is a 2D pattern that folds into a 3D shape. Drawing nets helps visualise surface area.
For a cylinder, the net consists of:
- Two circles (top and bottom)
- One rectangle (curved side)
The rectangle's width equals the circle's circumference: $2pi r$.
Check Understanding
Find the total surface area of a cylinder with radius 4 cm and height 10 cm.
Surface Area and Volume of Prisms and Cylinders
Find the surface area of a rectangular prism 5 cm × 4 cm × 3 cm.
$SA = 2(5 imes4 + 5 imes3 + 4 imes3)$
$= 2(20 + 15 + 12) = 2(47) = 94$ cm²
A cylinder has radius 3 cm and height 8 cm. Find its surface area.
$SA = 2pi(3)^2 + 2pi(3)(8)$
$= 18pi + 48pi = 66pi approx 207.3$ cm²
A triangular prism has cross-section area 12 cm², length 10 cm. Find volume.
$V = 12 imes 10 = 120$ cm³
Common Misconceptions
Use diameter instead of radius in cylinder formulas. All cylinder formulas use radius. If given diameter, halve it first.
Confuse surface area with volume. Surface area is the sum of face areas (units are cm²). Volume is the space inside (units are cm³).
Forget both circular ends of a cylinder. Total SA includes two circles: $2pi r^2$.
Practice — Prisms and Cylinders
Manufacturing and Packaging
Companies calculate surface area to determine material costs for boxes, cans, and containers. Minimising surface area reduces packaging costs and environmental impact. Australian recycling targets depend on efficient material use.
📓 Copy Into Your Books
▼Rectangular prism
- $SA = 2(lw + lh + wh)$
- $V = lwh$
Cylinder
- $V = pi r^2 h$
- $SA = 2pi r^2 + 2pi r h$
General prism
- $V = ext{cross-section area} imes ext{length}$
- $SA = ext{sum of all faces}$