The word ‘quad’ means four and the word lateral means sides. Thus, a plane figure bounded by four line segments AB, BC, CD and DA is called a quadrilateral and is written as quad. ABCD.

i) A i) AB

ii) B ii) BC

iii) C iii) CD

iv) D iv) DA

i) ∠A i) AC

ii) ∠B ii) BD

iii) ∠C

iv) ∠D

On the basis of diagonals, there are two types of quadrilaterals.

1) Convex

2) Concave

In

According to the given diagram, the adjacent sides are

i) AB, BC

ii) BC, CD

iii) CD, DA

iv) DA, AB

i) AB and CD

ii) AD and BC

are two pairs of opposite sides of the quadrilateral ABCD.

AC and BD are diagonals.

i) ∠A , ∠B

ii) ∠B, ∠C

iii) ∠C , ∠D

iv) ∠D , ∠ A

are four adjacent angles.

i) ∠A , ∠C

ii) ∠B , ∠D are two pairs of opposite angles of the quadrilateral ABCD.

• Introduction to Quadrilateral

• Types of Quadrilateral

• Properties of Quadrilateral

• Parallelogram and its Theorems

• Rectangle and its Theorems

• Square and its Theorems

• Rhombus and its Theorems

• Trapezoid (Trapezium)and its Theorems

• Kite and its Theorems

• Mid Point Theorem