QUADRILATERALS

Shapes with 4 Sides, 4 Corners and 4 Angles!
WHAT IS A QUADRILATERAL?

A quadrilateral is a closed 2D (flat) shape that has:

  • ✓ 4 sides
  • ✓ 4 corners (vertices)
  • ✓ 4 angles
Quad = Four
Quadrilateral = Shape with 4 sides
PARTS OF A QUADRILATERAL
A B C D
➔ Sides
AB, BC, CD, DA
➔ Vertices (Corners)
A, B, C, D
➔ Angles
∠A, ∠B, ∠C, ∠D
--➔ Diagonals
AC and BD
(Join opposite corners)
MEMORY TRICK
QUAD
=
FOUR
  • ★ 4 Sides
  • ★ 4 Corners
  • ★ 4 Angles
  • ★ 1 Closed Shape
TYPES OF QUADRILATERALS
1. SQUARE
A B C D
PROPERTIES
  • ★ 4 equal sides
  • ★ 4 right angles (90°)
  • ★ Opposite sides are parallel
EXAMPLES
Chessboard square
Floor tile
2. RECTANGLE
A B C D
PROPERTIES
  • ★ Opposite sides are equal
  • ★ 4 right angles (90°)
  • ★ Opposite sides are parallel
EXAMPLES
Door
Book
Mobile phone
Whiteboard
3. PARALLELOGRAM
A B C D
PROPERTIES
  • ★ Opposite sides are equal
  • ★ Opposite sides are parallel
  • ★ Opposite angles are equal
EXAMPLES
Slanted window
Decorative tiles
4. RHOMBUS
A B C D
PROPERTIES
  • ★ All 4 sides are equal
  • ★ Opposite angles are equal
  • ★ Angles are not always 90°
EXAMPLES
Diamond symbol
Kite pattern
5. TRAPEZIUM
(TRAPEZOID)
A B C D
PROPERTIES
  • ★ Only one pair of opposite sides is parallel
EXAMPLES
Bridge support
Lampshade
6. KITE
A B C D
PROPERTIES
  • ★ Two pairs of equal adjacent sides
  • ★ One pair of opposite angles are equal
EXAMPLES
Flying kite
Diamond shaped decoration
COMPARISON TABLE
Shape Equal Sides Right Angles Parallel Sides
Square 4 equal sides 4 right angles (90°) 2 pairs
Rectangle Opposite sides are equal 4 right angles (90°) 2 pairs
Parallelogram Opposite sides are equal No 2 pairs
Rhombus 4 equal sides Not always 2 pairs
Trapezium No Not always 1 pair
Kite Two pairs of adjacent equal sides No No
REMEMBER THESE FACTS
  • ★ Every square is a rectangle.
  • ★ Every square is a rhombus.
  • ★ Not every rectangle is a square.
  • ★ Not every rhombus is a square.
  • ★ Every quadrilateral has 4 sides.
  • ★ The sum of all angles of a quadrilateral is 360°.
All quadrilaterals are closed shapes.
KEY WORDS
  • Quadrilateral – A closed shape with four sides.
  • Side – A straight line forming the shape.
  • Vertex – A corner where two sides meet.
  • Angle – The space formed by two sides meeting.
  • Diagonal – A line joining opposite corners.
  • Parallel Lines – Lines that never meet.
  • Equal Sides – Sides of the same length.
QUICK CHECK (Fill in the blanks)
  1. 1. A quadrilateral has ______ sides.
  2. 2. A square has ______ equal sides.
  3. 3. A rectangle has ______ right angles.
  4. 4. A trapezium has ______ pair of parallel sides.
  5. 5. A kite has ______ pairs of equal adjacent sides.
ANSWERS: 1) 4   2) 4   3) 4   4) one   5) two
TRUE OR FALSE
  1. 1. Every square is a quadrilateral. T / F
  2. 2. Every rectangle has four right angles. T / F
  3. 3. A kite has four equal sides. T / F
  4. 4. A trapezium has one pair of parallel sides. T / F
  5. 5. Every quadrilateral has four corners. T / F
ANSWERS: 1) T   2) T   3) F   4) T   5) T
PRACTICE QUESTIONS
  1. 1. What is a quadrilateral?
  2. 2. Name any four quadrilaterals.
  3. 3. Which quadrilateral has four equal sides and four right angles?
  4. 4. Which quadrilateral has only one pair of parallel sides?
  5. 5. Which quadrilateral looks like a flying kite?
(Discuss and write the answers in your notebook.)
REAL-LIFE EVERYWHERE!
Window
Floor tile
Book
Kite
Bridge
Diamond symbol