Quadrilaterals are polygons with four sides.
Types of quadrilaterals
The table summarises the types and properties of quadrilaterals:
Name 
Properties 
Diagram 
Trapezium

 One pair of parallel sides


Isosceles trapezium

 One pair of parallel sides
 Other two sides equal in length
 Diagonals equal in length
 Base angles are equal


Cyclic Quadrilateral

 All four vertices lie on the circumference of a circle


Kite

 Two pairs of adjacent sides equal
 Diagonals intersect at right angles


Arrowhead

 Two pairs of adjacent sides equal
 One interior angle is reflex (bigger than 180°)


Parallelogram

 Opposite sides are parallel and equal
 Opposite angles are equal
 Diagonals bisect each other


Rhombus

 Opposite sides are parallel
 All sides are equal in length
 Opposite angles are equal
 Diagonals bisect each other at right angles


Rectangle

 Diagonals bisect each other
 All angles are right angles
 Opposite sides parallel and equal


Square 
 Opposite sides are parallel
 All sides are equal in length
 All angles are right angles
 Diagonals bisect at right angles

