2D SHAPES

Flat shapes that have length and width.

They do not have thickness or height.

PARTS OF A 2D SHAPE

Side
Vertex (Corner)
Angle

QUICK FACTS

  • 2D shapes are flat.
  • They have length and width.
  • A polygon is a closed shape made only of straight sides.
  • A circle is not a polygon.
TYPES OF 2D SHAPES

1. CIRCLE

  • A circle is a round, closed shape with no sides and no corners.
  • Sides: 0
  • Vertices: 0
  • Angles: 0
  • Has one continuous curved boundary.
  • All points on the boundary are at the same distance from the centre.

2. TRIANGLE

  • Sides: 3
  • Vertices: 3
  • Angles: 3
By Sides: Equilateral, Isosceles, Scalene
By Angles: Acute (all < 90°), Right (one = 90°), Obtuse (one > 90°)

3. SQUARE

  • Sides: 4 (all equal)
  • Vertices: 4
  • Angles: 4 right angles (90°)

4. RECTANGLE

  • Sides: 4
  • Opposite sides are equal
  • Vertices: 4
  • Angles: 4 right angles (90°)

5. PARALLELOGRAM

  • Sides: 4
  • Opposite sides are parallel and equal
  • Opposite angles are equal

6. RHOMBUS

  • Sides: 4 (all equal)
  • Opposite sides are parallel
  • Opposite angles are equal

7. TRAPEZIUM (TRAPEZOID)

  • Sides: 4
  • One pair of opposite sides are parallel

8. KITE

  • Sides: 4
  • Two pairs of equal adjacent sides
  • One line of symmetry

9. PENTAGON

  • Sides: 5
  • Vertices: 5

10. HEXAGON

  • Sides: 6
  • Vertices: 6

11. HEPTAGON

  • Sides: 7
  • Vertices: 7

12. OCTAGON

  • Sides: 8
  • Vertices: 8

13. NONAGON

  • Sides: 9
  • Vertices: 9

14. DECAGON

  • Sides: 10
  • Vertices: 10

POLYGON

A polygon is a closed 2D shape made only of straight sides.

Examples (Polygons): Triangle, Square, Pentagon, Hexagon

Not Polygons: Circle, Oval

OPEN AND CLOSED SHAPES

Open Shape: Ends do not meet

Closed Shape: Ends meet

REGULAR AND IRREGULAR SHAPES

Regular Shape: All sides equal. All angles equal.

Irregular Shape: Sides or angles are not all equal.

REAL-LIFE SHAPES

Circle → Wheel, Coin, Clock

Triangle → Traffic sign, Roof

Square → Chessboard, Tile

Rectangle → Book, Door

Pentagon → Badge

Hexagon → Honeycomb

Octagon → Stop sign

Kite → Flying kite

NUMBER OF SIDES, VERTICES AND ANGLES

Shape Name Sides Vertices Angles
Circle000
Triangle333
Square444
Rectangle444
Parallelogram444
Rhombus444
Trapezium444
Kite444
Pentagon555
Hexagon666
Heptagon777
Octagon888
Nonagon999
Decagon101010