Primary 1 2D Shapes
Look at the boundary of each flat shape. Trace it, count its corners, and describe what you notice.
Keywords
Say a shape's name, then trace its boundary to describe it.
- 2D shape
- A flat shape that can be drawn on paper.
- Rectangle
- A shape with four straight edges and four corners; opposite edges match in length.
- Square
- A shape with four straight edges of the same length and four corners.
- Triangle
- A shape with three straight edges and three corners.
- Circle
- A round shape with one curved boundary and no corners.
- Half circle
- One half of a circle, with one straight edge and one curved edge.
- Quarter circle
- One quarter of a circle, with two straight edges and one curved edge.
- Edge / corner
- Trace an edge along the boundary; point to where edges meet at a corner.
Show and name the shapes
First say the name. Then open a card and use your finger to trace its straight or curved edge. The orange dots show where edges meet.
RectangleShow properties ↓Hide properties ↑
Trace: Four straight edges and four corners.
Notice: The opposite edges are the same length.
Ask: “Which edges match?”
SquareShow properties ↓Hide properties ↑
Trace: Four straight edges and four corners.
Notice: All four edges are the same length.
Ask: “How is this different from the wide rectangle?”
TriangleShow properties ↓Hide properties ↑
Trace: Three straight edges and three corners.
Notice: It stays a triangle even when it is turned.
Ask: “Can you point to each corner as you count?”
CircleShow properties ↓Hide properties ↑
Trace: One continuous curved boundary.
Notice: No straight edges and no corners.
Ask: “Where would your finger stop as it goes around?”
Half circleShow properties ↓Hide properties ↑
Trace: One straight edge and one curved edge.
Notice: The edges meet at two ends. Two matching halves can make a circle.
Ask: “Which part is straight? Which part is curved?”
Quarter circleShow properties ↓Hide properties ↑
Trace: Two straight edges and one curved edge.
Notice: The two straight edges meet at a square corner. Four matching quarters can make a circle.
Ask: “How many straight edges can you trace?”
Guide for parents
Try this: Ask your child to name a shape before counting. Trace its boundary together, then ask which edges are straight or curved and where they meet. Turn the page or point from another direction to show that the shape keeps its name.
Common mistake: Calling a turned square a different shape. Rotate the page and check again: it still has four equal straight edges and four corners.
Keywords: rectangle, square, triangle, circle, half circle, quarter circle, straight edge, curved edge, corner.
Printable shapes
Print six shapes with their names inside. Cut along each outline, then turn and sort the pieces to explore their properties.
2D shape cut-outs
Cut carefully along each shape outline. Turn and sort the pieces.