19.6 Composite shapes and solids — Practise with help
Warm-up: remember
- Find the volume of a cuboid cm. 2. Find the area of a cm by cm rectangle.
Check your answers
- . 2. .
Practise with help
Attempt each question first. Open the hint, then the next step, when needed.
1. A shape is made from a 5 cm by 4 cm rectangle and a 5 cm by 3 cm rectangle joined along a 5 cm side without overlap. Work out its total area.
Hint
Split the shape into its two rectangles and add their areas.
Next step
Find .
Full working
.
2. A solid is made from a cuboid 6 cm by 4 cm by 3 cm and a cuboid 2 cm by 4 cm by 3 cm joined without overlap. Work out its total volume.
Hint
Find each cuboid's volume, then add them.
Next step
Find .
Full working
.
3. A semicircle of radius 3 cm is joined to a rectangle 6 cm by 4 cm along the 6 cm side. Work out the outside perimeter in terms of π.
Hint
The outside is the arc plus the three straight sides that are not joined.
Next step
Find the arc as half the circumference: .
Full working
The straight part is . The outside perimeter is .
Try the remaining questions without opening the full working.