Quadrilaterals

A quadrilateral is a polygon which has 4 vertices and 4 sides enclosing 4 angles. The sum of its interior angles of a quadrilaterl is 360 degree.

Types of Quadrilaterals

• Trapezium: It is a quadrilateral with one pair of opposite parallel sides. In the trapezium ABCD, side AB is parallel to side CD.

• Parallelogram: It is a quadrilateral with two pairs of parallel sides. 
• The opposite sides are parallel and equal in length. 
• The opposite angles are equal in measure. In the parallelogram ABCD, side AB is parallel to side CD and side AD is parallel to side BC.
• Also, the two diagonals formed intersect each other at the midpoints. As in the figure given below, E is the point where both the diagonals meet. So
  Length AE = EC, & Length BE = ED

• Rectangle: It is a quadrilateral with all the 4 angles of equal measure, that is, each of them is 90°. 
• Both the pairs of opposite sides are parallel and equal in length.

• Rhombus: It is a quadrilateral with all the four sides having equal lengths. 
• The Opposite sides of a rhombus are parallel and opposite angles are equal.

• Square: It is a quadrilateral in which all the sides and angles are equal. 
• Every angle is a right angle (i.e. 90° each). 
• The pairs of opposite sides are parallel to each other.

• Kite: It is a quadrilateral that has 2 pairs of equal-length sides and these sides are adjacent to each other.