4
What shape am I?
Learner’s Book 1: Unit 10, pp. 145–146
GoalUse clues about faces to find a shape, and make your own clues.
New words
clue · a hint that helps you find the answertower · shapes stacked one on top of the otherdescribe · say what something is like
Explanation
We can describe a shape with clues about its faces, its edges and whether it rolls. A clue could be: I have a point at the top and a square at the bottom. That is a square pyramid. Another clue: I can roll, and I can also stand flat on a circle. That is a cylinder. A good set of clues fits only one shape. Try making your own clues for a friend.
| clue | shape |
|---|---|
| a point at the top, a square at the bottom | square pyramid |
| rolls, and stands flat on a circle | cylinder |
Worked examples
What am I? I look like a box. I have 6 faces, and some of them are long rectangles. I am a cuboid.
What am I? I have 12 edges, and they are all the same length. I am a cube.
A clue must fit only one shape. ‘I have flat faces’ fits a cube, a cuboid and a pyramid, so we need another clue.
Class activity
Mystery bag: put a dice, a tin, a ball, a box and a toy tent in a bag. Without looking, feel one shape and give clues: how many flat faces, and is there a curved surface? Your partner guesses the shape. Then swap.
Practice
1
Here is a clue: I have a point at the top. Does the clue fit this shape?
No. A cylinder has no point. The clue fits a pyramid.
2
What shape am I? I stand on a square, and my 4 triangle sides lean in to a point.
a square pyramid
3
What shape am I? I have no flat faces and I roll.
a sphere
4
Write two clues for this shape.
For example: I have 6 flat faces. My faces are rectangles.