1
Turning shapes around
Learner’s Book 1: Unit 10, p. 147
GoalSay that a shape is still the same shape when it is turned, and know which shapes fit together with no gaps.
New words
rotate · turn a shape aroundgap · an empty space between shapesrectangle · a shape with 4 straight sides and 4 square corners
Explanation
A 2D shape is flat, like a shape drawn on paper. When you turn a shape around, we say you rotate it. After a turn it may point a new way, but its name does not change. A triangle turned upside down is still a triangle. Squares and triangles can sit snugly side by side, with no empty spaces. Circles cannot: there is always a little space between them. Tiles on a kitchen floor are often squares for this reason.
Worked examples
Squares fit together with no gaps. That is why they are good for a floor.
Circles leave gaps between them, even when they touch. Look at the little space in the middle.
A rectangle turned on its side is still a rectangle.
Class activity
Tile game: cut out 10 squares or triangles from paper. Make a pattern on the table so that the shapes touch with no gaps. Turn some of them around (rotate them) to change the pattern. Now try with paper circles. What do you notice?
Practice
1
How many triangles are in this pattern?
7
2
Do circles fit together with no gaps?
No, circles always leave gaps.
3
A rectangle is turned around. Is it still a rectangle?
Yes. Turning does not change the shape.
4
Mia wants to cover a floor with tiles and leave no gaps. Should she use squares or circles?
Squares.