A quadrilateral has four-sides, it is 2-dimensional (a level shape), closed (the lines join up), and has straight sides.

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A quadrilateral has:

4 sides (edges) four vertices (corners) inner angles that include to 360 degrees:


Try illustration a quadrilateral, and also measure the angles. Castle should add to 360°

Types that Quadrilaterals

There space special types of quadrilateral:


Some types are additionally included in the an interpretation of other types! For example a square, rhombus and also rectangle are also parallelograms. See listed below for more details.

Let us look in ~ each form in turn:

The Rectangle

the small squares in each edge mean "right angle"

A rectangle is a four-sided form where every angle is a appropriate angle (90°).

Also the contrary sides room parallel and of same length.

The Square

the tiny squares in each corner mean "right angle"

A square has actually equal sides (marked "s") and every angle is a ideal angle (90°)

Also opposite sides are parallel.

A square additionally fits the an interpretation of a rectangle (all angles space 90°), and also a rhombus (all sides room equal length).

The Rhombus


A rhombus is a four-sided shape where every sides have equal size (marked "s").

Also the contrary sides are parallel and also opposite angles room equal.


Another interesting thing is the the diagonals (dashed lines) accomplish in the middle at a appropriate angle. In various other words they "bisect" (cut in half) each various other at ideal angles.

A rhombus is sometimes called a rhomb or a diamond.

The Parallelogram


A parallelogram has actually opposite sides parallel and equal in length. Likewise opposite angles are equal (angles "A" are the same, and also angles "B" room the same).

NOTE: Squares, Rectangles and Rhombuses room all Parallelograms!


A parallelogram with:

all sides equal andangles "A" and "B" as ideal angles

is a square!

The Trapezoid (UK: Trapezium)


Isosceles Trapezoid

A trapezoid (called a trapezium in the UK) has actually a pair the opposite political parties parallel.

And a trapezium (called a trapezoid in the UK) is a quadrilateral through NO parallel sides:

In the US:a pair of parallel sidesNO parallel sides
In the UK:NO parallel sidesa pair of parallel sides
(the US and also UK interpretations are swapped over!)

An Isosceles trapezoid, as shown above, has actually left and also right political parties of equal size that sign up with to the basic at equal angles.

The Kite


Hey, the looks favor a dragon (usually).

It has two pairs the sides:

Each pairis do of 2 equal-length sides that join up.


the angles whereby the two pairs satisfy are equal.the diagonals, presented as dashed present above, satisfy at a right angle.one of the diagonals bisects (cuts same in half) the other.

... And that"s it because that the unique quadrilaterals.

Irregular Quadrilaterals

The only constant (all sides equal and all angles equal) quadrilateral is a square. So all various other quadrilaterals space irregular.

The "Family Tree" Chart

Quadrilateral interpretations are inclusive.

Example: a square is also a rectangle.

So we include a square in the meaning of a rectangle.

(We don"t speak "Having all 90° angles renders it a rectangle other than when every sides room equal then it is a square.")

This may seem odd, as in daily life we think that a square as not being a rectangle ... Yet in math it is.

Using the chart listed below we can answer such concerns as:

Is a Square a kind of Rectangle? (Yes) Is a Rectangle a kind of Kite? (No)


Complex Quadrilaterals

Oh Yes! as soon as two political parties cross over, we call it a "Complex" or "Self-Intersecting" quadrilateral, choose these:


They still have actually 4 sides, but two sides cross over.


A quadrilateral is a polygon. In fact it is a 4-sided polygon, just like a triangle is a 3-sided polygon, a pentagon is a 5-sided polygon, and also so on.

See more: Why Was Ron Was Upset That Harry Was A Parselmouth Because, Ginevra Weasley

Play with Them

Now the you recognize the different types, you can play with the interaction Quadrilaterals.

Other Names

A quadrilateral have the right to sometimes it is in called:

a Quadrangle ("four angles"), so the sounds favor "triangle" a Tetragon ("four polygon"), so that sounds prefer "pentagon", "hexagon", etc.
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polygons Interactive Quadrilaterals ideal Angle Parallel parallelogram In any Quadrilateral Geometry Index