LEARN THINGS THE EASY WAY

By the end of this lesson, you will be able to

• classify different types of quadrilateral.

A four-sided polygon with four vertices is a quadrilateral. A quadrilateral is a special polygon in terms of Edges and angles.

Quadrilaterals are generally divided into two parts in terms of self-intersecting:

A quadrilateral is said to be a simple quadrilateral if it is not self-intersecting.

Simple quadrilaterals are, again, divided into two parts:

A convex quadrilateral is a quadrilateral in which all interior angles are less than 180° and both diagonals lie inside the quadrilateral.

A few properties of convex properties are given below:

• Four edges or sides.
• Four vertices or corners.
• Two diagonals.
• Two diagonals both must lie inside the quadrilateral.
• Each interior angle is less than 180°.
• All interior angles add up to 360°.

A concave quadrilateral is a quadrilateral in which one of the two diagonals is outside the quadrilateral and one interior angle is greater than 180° and less than 360°.

An angle θ, 180°<θ<360° and a diagonal is outside of quadrilateral.

It is also well-known as crossed-quadrilateral.

In a complex quadrilateral, there are two reflex and other two angles are acute among the four interior angles.

And these four interior angles add up to 720°.

An irregular quadrilateral that has no parallel sides.

An irregular quadrilateral in the figure because this quadrilateral has no parallel sides.

There are several types of quadrilaterals in plane geometry.

And there are few properties in common and uncommon for different types of quadrilaterals.

All quadrilaterals must have, for instance, four edges and four vertices. And these are common properties for all quadrilaterals.

All interior angles, for example, are less than 1800 for some quadrilaterals.

On the other hand, one interior angle is greater than 1800 for several quadrilaterals.