A square has four-sides, that is 2-dimensional (a flat shape), closed (the lines join up), and has straight sides.

You are watching: A quadrilateral with one right angle must be a rectangle

(Also view this on interaction Quadrilaterals)

## Properties

4 sides (edges) 4 vertices (corners) internal angles that include to 360 degrees: Try drawing a quadrilateral, and measure the angles. Lock should include to 360°

There are special species of quadrilateral: Some species are also included in the definition of other types! For example a square, rhombus and also rectangle are additionally parallelograms. See listed below for much more details.

Let us look in ~ each form in turn:

## The Rectangle the little squares in each edge mean "right angle"

A rectangle is a four-sided shape where every angle is a best angle (90°).

Also opposite sides room parallel and of same length.

## The Square

the small squares in each corner mean "right angle"

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

Also the contrary sides are parallel.

A square likewise fits the definition of a rectangle (all angles space 90°), and a rhombus (all sides room equal length).

## The Rhombus A rhombus is a four-sided shape where all sides have actually equal size (marked "s").

Also the contrary sides are parallel and also opposite angles are equal. Another interesting thing is that the diagonals (dashed lines) meet in the center at a appropriate angle. In various other words lock "bisect" (cut in half) each various other at appropriate angles.

A rhombus is sometimes referred to as a rhomb or a diamond.

## The Parallelogram A parallelogram has opposite political parties parallel and equal in length. Also opposite angles are equal (angles "A" are the same, and also angles "B" space the same).

NOTE: Squares, Rectangles and also Rhombuses are all Parallelograms!

### Example:

A parallelogram with:

all sides equal andangles "A" and also "B" as right angles

is a square!

## The Trapezoid (UK: Trapezium)  TrapezoidIsosceles 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:

 Trapezoid Trapezium In the US: a pair that parallel sides NO parallel sides In the UK: NO parallel sides a pair the parallel sides (the US and also UK meanings are swapped over!)

An Isosceles trapezoid, as displayed above, has actually left and right political parties of equal length that sign up with to the base at same angles.

## The Kite Hey, the looks favor a kite (usually).

It has actually two pairs the sides:

Also:

the angles wherein the 2 pairs meet are equal.the diagonals, shown as dashed present above, accomplish at a right angle.one that the diagonals bisects (cuts same in half) the other.

... And that"s it for the special quadrilaterals.

The only consistent (all sides equal and all angle equal) square is a square. Therefore all other quadrilaterals space irregular.

## The "Family Tree" Chart

### Example: a square is likewise a rectangle.

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

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

This may seem odd, as in daily life us think of a square together not gift a rectangle ... Yet in math it is.

Using the chart below we deserve to answer such concerns as:

Is a Square a kind of Rectangle? (Yes) Is a Rectangle a kind of Kite? (No) Oh Yes! once two political parties cross over, we call it a "Complex" or "Self-Intersecting" quadrilateral, choose these: They still have actually 4 sides, yet two political parties cross over.

## Polygon

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

See more: How Far Will A 223 Shoot Ing 1400 Yards With A, How Far Can A 223 Bullet Travel

## Play with Them

Now that you understand the various types, you have the right to play with the interactive Quadrilaterals.

## Other Names

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

a Quadrangle ("four angles"), so it sounds choose "triangle" a Tetragon ("four polygon"), so the sounds choose "pentagon", "hexagon", etc.
621,622,623,624,763,764, 2128, 2129, 3230, 3231
polygons Interactive Quadrilaterals ideal Angle Parallel parallelogram In any Quadrilateral Geometry Index