Solids, flat shapes and position · Usually met around P1
3D shapes
Curved faces roll; flat top and bottom stack.
How to do it
Method
Curved faces roll; flat top and bottom stack
A can is a cylinder: it rolls and it stacks
Another way
Compare with things around you
A ball is a sphere, an ice-cream cone a cone
In full
Know a solid by its faces: every face of a cube or a cuboid is flat; a cylinder has a circle at each end and a curved side; a cone has a circular base and a point; a sphere is curved all over; a prism has the same shape at both ends, and a pyramid comes to a point. A curved face lets it roll: a sphere rolls any way, a cylinder rolls straight, a cone rolls round its point. Only solids that are flat top and bottom stack steadily. Or compare with things around you: a can is a cylinder, an ice-cream cone is a cone.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
What solid is in the picture?
- A. Cone
- B. Cylinder
- C. Cube
- D. Sphere
Choose the right answer
Show the answer and working
Answer: D. Sphere
Look at its faces: flat or curved, and whether it has a point.
Example 2
What solid is in the picture?
- A. Triangular prism
- B. Cuboid
- C. Cube
- D. Square pyramid
Choose the right answer
Show the answer and working
Answer: A. Triangular prism
Look at the shape of its ends and whether it has a point.
Example 3
Two of the solid in the picture can be stacked steadily, one on top of the other.
True or false?
Show the answer and working
Answer: True
Only flat top and bottom (cube, cuboid, cylinder) stack steadily; a point or an all-curved shape won't.
Practise it in the game →Solids, flat shapes and position · Free to start, unlimited questions, no download