quadrilateral types

NEGATIVE EXAMPLES POSITIVE EXAMPLES

TYPES OF QUADRILATERALS

• The origin of the word “quadrilateral” is the two latin words

quadr i - a variant of four &

• latus – side

• A closed four sided figure is called a quadrilateral

• A quadrilateral is a polygon that has exactly four sides, exactly

four vertices & exactly four angles.

RECTANGLE

TRAPEZIUM

PARALLELOGRAM

SQUARE

RHOMBUS

Side AB = Side BC =Side CD =Side AD

<A = < B = <C = <D = 90°

A quadrilateral with all sides congruent and each angle a right angle is called a square.

l (AC) = l (BD)

l (AO) = l (OC) , l (BO) = l (OD)

m <AOD = m <DOC = m <BOC = m <BOA = 90°

<P = <Q = <R = <S = 90°

Side PQ = Side SR , Side PS = Side QR

A quadrilateral with each angle a right angle and opposite sides congruent is called a rectangle.

Side PQ = Side SR , Side PS = Side QR

Diagonal PR = Diagonal QS

l (PO) = l (OR) , l (SO) = l (OQ)

Side PQ = Side QR = Side RS = Side PS

A quadrilateral having all sides congruent is called a rhombus.

PROPERTIES OF A RHOMBUS

l (PO) = l (OR) , l (QO) = l (OS)

m <POS = m <SOR = m <ROQ = m <QOP = 90°

m <SPQ = m <SRQ , m <PSR = m <PQR

B

D

C

Side AB // Side CD , Side AD // Side BC

A quadrilateral which has opposite sides parallel is called a parallelogram.

Seg AB = Seg DC , Seg AD = Seg BC.

< A = < C , < B = <D.

l( AO) = l(CO) , l(BO) = l(DO)

B

D

C

O

Sr.no. Quadrilaterals

Properties of quadrilaterals

RECAPITULATION

1)

1) The diagonals of a square are congruent.

2) The diagonals of a square bisect each other.

3) Each diagonal of a square is the perpendicular

bisector of the other.Square

2)

Rectangle

2) The diagonals of a rectangle are congruent.

1) The opposite sides of a rectangle are congruent.

3) The diagonals of a rectangle bisect each other.

Sr.no. Quadrilaterals

Properties of quadrilaterals

CONTD…

3)

1) The diagonals of a rhombus bisect each other.

2) Each diagonal of a rhombus is the perpendicular

bisector of the other.

3) The opposite angles of a rhombus are equal.

4)1) The opposite sides of a parallelogram are congruent.

2) The opposite angles of a parallelogram are congruent.

3) The diagonals of a parallelogram bisect each other.Parallelogram

evaluationA) Define quadrilaterals?B) State the properties of a rectangle?C) State the properties of a rhombus?D) Look at the figure of the rhombus and answer the following

questions

A

B C

D

O

1) Length of side AD = 4cm. Then what are theLengths of sides AB, BC, CD ?

2) m<AOD = ?

3) IF l(BO) =2.5 , THEN l(BD) = ?