Quadrilateral is a term used in geometry. It is a polygon which has four sides and four vertices. They are mostly in two types one is simple and the other is complex, which is self-intersecting. Simple quadrilaterals are basically either convex or concave. Convex quadrilaterals are further divided into Trapezium (where no sides are parallel), trapezoid, (where one pair of opposite sides is parallel), Isosceles trapezium (two of the contradictory sides are corresponding, the two other sides are equivalent, and the two ends of each corresponding side have equivalent angles).

Next is, parallelogram, where both contradicting sides are parallel. Subsequent is Kite where two adjoining sides have one and the same length; the other two sides have identical length, Rhombus where all the four sides are equal in length. Rectangle also known as Oblong where each of its angle is a right angle. Next is Square where all the sides are equal.

A qua drilaterals has four sides,four angels and four vertices. In quadrilaterals abcd, ab, bc, cd , and da are the four sides abc and d are four vertices and angelsA angelsB ANGELsC ANGELsD.are four angels formed at the vertices .

Trapezium (where no sides are parallel), trapezoid, (where one pair of opposite sides is parallel), Isosceles trapezium (two of the contradictory sides are corresponding, the two other sides are equivalent, and the two ends of each corresponding side have equivalent angles). Parallelogram, where both contradicting sides are parallel. Subsequent is Kite where two adjoining sides have one and the same length; the other two sides have identical length, Rhombus where all the four sides are equal in length. Rectangle also known as Oblong where each of its angle is a right angle. Next is Square where all the sides are equal. This is want to main mathematical shapes