Which two-dimensional figure is being described?
key notes :
What is a Two-Dimensional (2D) Figure?
- A flat shape that only has length and width.
- It does not have depth or thickness.
- Examples: Square, Rectangle, Triangle, Circle, etc.
Common 2D Shapes and Their Properties:
| Shape | Number of Sides | Number of Corners (Vertices) | Special Features |
|---|---|---|---|
| Triangle | 3 | 3 | Can have equal or unequal sides |
| Square | 4 | 4 | All sides equal; all angles 90° |
| Rectangle | 4 | 4 | Opposite sides equal; 90° angles |
| Circle | 0 | 0 | Round; no corners or straight sides |
| Pentagon | 5 | 5 | Five sides and five corners |
| Hexagon | 6 | 6 | Six sides and six corners |
| Octagon | 8 | 8 | Eight sides and eight corners |
How to Identify a 2D Shape from a Description
Ask:
- How many sides does it have?
- Are the sides equal?
- How many angles or corners?
- Are the angles right angles (90°)?
- Is the shape round or straight-edged?
Clue Words to Watch For:
- Equal sides → Square
- Four sides, opposite sides equal → Rectangle
- Three sides → Triangle
- No corners or sides → Circle
- Five sides → Pentagon
- Six sides → Hexagon
- Eight sides → Octagon
Example Descriptions:
- “A shape with four equal sides and all right angles.” → Square
- “A flat shape with no corners and no sides.” → Circle
- “A polygon with five sides.” → Pentagon
Learn with an example
🎯 Roger saw a shape with 7 sides. Which shape could Roger have seen?
Look at the heptagon:
It has 7 sides. Roger could have seen a heptagon.
Roger could not have seen these figures:
🎯 Jerry drew a shape on the chalkboard. The shape had 5 angles. Which shape could Jerry have drawn?
Look at the Pentagon:
It has 5 angles. Jerry could have drawn a pentagon.
Jerry could not have drawn these figures:
🎯 Brittany drew a shape on the chalkboard. The shape had 3 sides. Which shape could Brittany have drawn?
Look at the triangle:
It has 3 sides. Brittany could have drawn a triangle.
Brittany could not have drawn these figures:
let’s practice!
