A Quadrilateral is a four sided shape which can be made from 2 triangles

The angles add up to 2 X 180 = 360º

A

B

C

D

A + B + C + D =360

The area =sum of the areas of the two triangles

It fits inside a circle

square rectangle rhombus

parallelogramIsosceles Trapezium

with symmetry

Trapezium

without symmetry

The following quadrilaterals have properties which make them special

kite

4 equal sides

Angles are = 90º

Diagonals are equal

Diagonals bisect each other at 90 º

THE SQUARE

4 lines of symmetry and quarter turn symmetry

Fits outline 8 ways

Opposite sides equal and parallel=

=

=

=9090

9090

The rectangle

Opposite sides equal and parallel

Angles are = 90º

Diagonals are equal

Diagonals bisect each other

2 lines of symmetry and half turn symmetry

Fits outline 4ways

=

==

=

The rhombus

4 equal sides

Opposite sides equal and parallel

Opposite angles are equal

Diagonals bisect each other at 90 ºDiagonals bisect the angles

2 lines of symmetry and HALF turn symmetry

Fits outline 4 ways

X X

Y

Y

The parallelogram

Opposite sides equal and parallel

Opposite angles are equal

Diagonals bisect each other

half turn symmetry

Fits outline 2 ways

X

XY

Y=

=

The Kite

==

X X

2 pairs of adjacent equal sides

One pair of opposite angles are equal

One diagonal bisects the other one at 90 ºOne diagonal bisecst the angles

1 line of symmetry

Fits outline 2 way

= =

The isosceles trapezium

X X

Y Y

One pair of parallel sides1 pairs of equal opposite sides

two pairs of adjacent angles are equal

diagonals are equal

1 line of symmetry

Fits outline 2 way

The trapezium

One pair of parallel sides