A quadrilateral is a closed figure formed by the intersection of four line segments.
Quadra means four and lateral means sides.
In the above figure 1, a quadrilateral is formed by the intersection of four line segments AB, BC, CD and DA.
A, B, C and D are four corners of the quadrilateral formed by the intersection of the four straight lines AB, BC, CD and DA.
How do you call the above figure?
That is how, a quadrilateral is called by naming its four corners prefixed with the word Quadrilateral, just as we would say ‘Triangle ABC’.
A quadrilateral is a four sided closed figure formed in one same plane. No two line segments out of the four AB, BC, CD and AD are collinear, i.e. lie on a same straight line.
Note the following terms in a quadrilateral
O is called the point of intersection of the diagonals of the quadrilateral.
In the quadrilateral ABDC below, if CD is base, then straight line AE perpendicular to CD is Height or Altitude.
Various Types of Quadrilaterals:
The following are the several types of quadrilaterals.
1. Irregular Quadrilateral
A quadrilateral in which all sides and angles are unequal is an irregular
A quadrilateral in which one pair of sides is parallel.
It is a quadrilateral in which
It is a parallelogram in which
A parallelogram in which