POLYGONS
INDEX
1.-POLYGONS
2.-TYPES OF POLYGONS
REGULAR E IRREGULAR
3.-NAMES OF POLYGONS
4.-TRIANGLES
5.-QUADRILATERALS
6.-REGULAR POLYGONS
7.-STAR POLYGONS
8.-KAMAL ALI
POLYGONS
Polygons are 2-dimensional shapes. They are made of straight lines,
and the shape is "closed" (all the lines connect up).
DEFINITION
Polygon (straight sides)
Not a Polygon (has a curve)
Not a Polygon (open, not closed)
Polygon comes from Greek. Poly- means "many" and -gon means "angle".
Regular and Irregular
If all angles are equal and all sides are equal,
then it is regular, otherwise it is irregular
REGULAR IRREGULAR
Types of Polygons
Name Sides Shape Interior Angle
Triangle (or Trigon) 3 60°
Quadrilateral (or Tetragon) 4 90°
Pentagon 5 108°
Hexagon 6 120°
Heptagon (or Septagon) 7 128.571°
Octagon 8 135°
Nonagon (or Enneagon) 9 140°
Decagon 10 144°
Hendecagon (or Undecagon) 11 147.273°
Dodecagon 12 150°
NAMES OF POLYGONS
Equilateral, Isosceles and Scalene
There are three special names given to triangles that tell how many
sides (or angles) are equal.
There can be 3, 2 or no equal sides/angles:
Equilateral Triangle
Three equal sides Three equal angles
Isosceles Triangle
Two equal sides Two equal angles
Scalene Triangle
No equal sides No equal angles
TYPES OF TRIANGLES
TRIANGLES
A triangle has three sides and three angles. The three angles
always add to 180º
Acute Triangle
All angles are less than 90°
Right Triangle
Has a right angle (90°)
Obtuse Triangle
Has an angle more than 90°
Triangles can also have names that tell you what type of angle is inside:
Properties •Four sides (or edges)
•Four vertices (or corners).
•The interior angles add up to
360 degrees:
Types of Quadrilaterals There are special types of quadrilateral:
QUADRILATERALS
QUADRILATERALS ARE CUADRILATEROS , HERE YOU WILL FIND THE
NAMES IN SPANISH TO COMPARE THEM
The Rectangle
A rectangle is a
four-sided shape
where every angle is
a right angle (90°).
Also opposite
sides are parallel an
d of equal length.
The Rhombus
A rhombus is a four-sided shape where all
sides have equal length.
Also opposite sides are
parallel and opposite angles are equal.
The Square
A square has equal
sides and every angle is
a right angle (90°)
Also opposite sides are
parallel.
A square also fits the
definition of
a rectangle (all angles
are 90°), and
a rhombus (all sides are
equal length).
The Parallelogram
Opposite sides are parallel and equal in length, and
opposite angles are equal (angles "a" are the same,
and angles "b" are the same)
The Trapezoid
(UK: Trapezium)
A trapezoid (called a trapezium in the UK) has
one pair of opposite sides parallel.
It is called an Isosceles trapezoid if the sides
that aren't parallel are equal in length and both
angles coming from a parallel side are equal, as
shown.
Language Note: In the US a "trapezium" is a
quadrilateral with NO parallel sides!
REGULAR POLYGONS
CONSTRUCTIONS
GENERAL METHOD OF CONSTRUCTION OF REGULAR POLYGONS
STAR POLYGONS
CONSTRUCTIONS
SOME EXEMPLES OF
DIFFERENTS
DESIGNS USING STAR
POLYGONS
KAMAL ALI PATTERN