Primary 1 maths · Geometry · About 8 minutes
Recognise rectangles, squares, triangles, circles, half-circles and quarter-circles
Look at the whole shape, even after it turns.
Start the interactive lesson →Open practice activity
What you will learn
- Recognise rectangles, squares, triangles, circles, half-circles and quarter-circles
Models used: number sentences, stories, diagrams.
A turn does not change the shape
Look for straight sides, corners and curved boundaries.
Look for straight sides, corners and curved boundaries.
Follow the sides and corners. Turn the shape. Its sides are still the same length, and its corners have the same openings.
Turning a figure changes where it points. It keeps its side lengths and corner angles, so it is still the same shape.
Follow the sides and corners. The same figure, turned through 25 degrees. Use those features to recognise the shape, whichever way it is turned.
Turning a figure changes where it points. It keeps its side lengths and corner angles, so it is still the same shape.
Follow the sides and corners. Changing orientation preserves the shape.
What did the picture help us see?
Use those features to recognise the shape, whichever way it is turned.
Worked example: A new example, together
Name the shape shown.
Look at the whole shape, even after it turns.
A shape is classified by its defining features, not its orientation.
A turn of the page does not change the shape. Inspect straight sides and curved boundaries.
A turn of the page does not change the shape. Name the shape shown.
quarter-circle
One quarter of a circle with two radii.
A turn of the page does not change the shape. The shape is a quarter-circle.
A turn of the page does not change the shape. Check the result against the question we started with.
Turn the figure mentally; its sides and corners are unchanged.
We found quarter-circle. A shape is classified by its defining features, not its orientation.
A turn of the page does not change the shape.
Common mistakes to discuss
- A turned shape gets a new name. Turning a shape does not change what it is. A square resting on a corner is still a square.
Check your understanding
- Recognise rectangles, squares, triangles, circles, half-circles and quarter-circles
- recognise a shape in different positions
- check the answer against the original quantities and units
Explain your reasoning to an adult, then try a fresh question in the interactive lesson. A result from one attempt is not proof of lasting mastery.
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