What Is The Formula Of A Polygon?

How do you tell if it is a polygon?

Polygons are two-dimensional objects, not solids.

Polygons are classified and described by the number of sides, the kind of angles, and whether any of the sides are the same length (or congruent).

Many polygons have special names.

This figure shows the most common polygons..

What is the formula of irregular polygon?

To find the area of an irregular polygon you must first separate the shape into regular polygons, or plane shapes. You then use the regular polygon area formulas to find the area of each of those polygons. The last step is to add all those areas together to get the total area of the irregular polygon.

What is an irregular polygon?

A regular polygon is a shape that has all sides and angles the same size. An irregular polygon is a shape that has different sized angles and sides.

What’s a 20 sided shape called?

icosagonIn geometry, an icosagon or 20-gon is a twenty-sided polygon. The sum of any icosagon’s interior angles is 3240 degrees.

What makes a polygon irregular?

A polygon that does not have all sides equal and all angles equal. (A polygon is “regular” only when all angles are equal and all sides are equal, otherwise it is irregular.)

Is Heptagon same as septagon?

A heptagon is a seven-sided polygon. It is also sometimes called a septagon, though this usage mixes a Latin prefix sept- (derived from septua-, meaning “seven”) with the Greek suffix -gon (from gonia, meaning “angle”), and is therefore not recommended.

What’s a 13 sided shape called?

tridecagonIn geometry, a tridecagon or triskaidecagon or 13-gon is a thirteen-sided polygon.

What is a irregular shape?

An irregular shape is a shape which has sides and angles of any length and size.

What is the formula for regular polygon?

You also learned the formula for finding the area of any regular polygon if you know the length of one side and the apothem: A = (n × s × a)2 A = ( n × s × a ) 2 , where n is the number of sides, s is the length of one side, and a is the apothem.

How do you find the Apothem of a polygon?

More Formulas We can also use the area formula to find the apothem if we know both the area and perimeter of a polygon. This is because we can solve for a in the formula, A = (1/2)aP, by multiplying both sides by 2 and dividing by P to get 2A / P = a. Here, the apothem has a length of 4.817 units.

What is a 99 sided shape called?

enneacontagonIn geometry, an enneacontagon or enenecontagon or 90-gon (from Ancient Greek ἑννενήκοντα, ninety) is a ninety-sided polygon.

What are the names of irregular polygons?

Irregular polygons can still be pentagons, hexagons and nonagons, but they do not have congruent angles or equal sides. Here are some examples of irregular polygons.

How do you know if a shape is not a polygon?

A figure or shape is not considered a polygon if it has rounded sides or if its sides intersects at any place other than at the ends of each side. Therefore a circle is not a polygon and an hourglass shape is not a polygon.

Is a circle a regular polygon?

A polygon is a closed plane figure with three or more sides that are all straight. A circle is not a polygon as it does not have straight sides. …

What is an irregular hexagon?

A hexagon is a shape with six sides. In a regular hexagon, all six sides are equal. An irregular hexagon is a six-sided shape whose sides are not equal.

What is the formula for the area of a polygon?

To find the area of a regular polygon, all you have to do is follow this simple formula: area = 1/2 x perimeter x apothem. Here is what it means: Perimeter = the sum of the lengths of all the sides. Apothem = a segment that joins the polygon’s center to the midpoint of any side that is perpendicular to that side.

What is the Apothem of a polygon?

The apothem (sometimes abbreviated as apo) of a regular polygon is a line segment from the center to the midpoint of one of its sides. Equivalently, it is the line drawn from the center of the polygon that is perpendicular to one of its sides. The word “apothem” can also refer to the length of that line segment.

What is a 5 sided shape called?

pentagonMore than Four Sides A five-sided shape is called a pentagon. A six-sided shape is a hexagon, a seven-sided shape a heptagon, while an octagon has eight sides…

What is an irregular Heptagon?

An irregular heptagon is any heptagon with sides and angles that are not all congruent.

What is a 1 sided shape called?

henagon monogonList of n-gons by Greek numerical prefixesSidesNames1henagonmonogon2digonbigon3trigontriangle4tetragonquadrilateral7 more rows

What are the 20 kinds of polygons?

Terms in this set (18)Three. Trigon or Triangle.Four. Tetragon or Quadrilateral.Five. Pentagon.Six. Hexagon.Seven. Heptagon.Eight. Octagon.Nine. Nonagon or Enneagon.Ten. Decagon.More items…

How many sides has a regular polygon?

Names of Regular PolygonsRegular PolygonNumber of SidesInterior AnglesEquilateral triangle3 sides3 interior angles of 60°Square4 sides4 interior angles of 90°Regular pentagon5 sides5 interior angles of 108°Regular hexagon6 sides6 interior angles of 120°2 more rows

What is a regular polygon shape?

In Euclidean geometry, a regular polygon is a polygon that is equiangular (all angles are equal in measure) and equilateral (all sides have the same length). Regular polygons may be either convex or star.

Is a star a regular polygon?

In geometry, a star polygon is a type of non-convex polygon. … Only the regular star polygons have been studied in any depth; star polygons in general appear not to have been formally defined, however certain notable ones can arise through truncation operations on regular simple and star polygons.

What are the names of polygons?

Here is a list of polygon names depending on the number of sides they have, starting with three and ending with ten.3 sides – Triangle.4 sides – Quadrilateral.5 sides – Pentagon.6 sides – Hexagon.7 sides – Heptagon.8 sides – Octagon.9 sides – Nonagon.10 sides – Decagon.