# Question: Why Is A Triangle Not A Polygon?

## Is any 6 sided shape a hexagon?

In geometry, a hexagon (from Greek ἕξ hex, “six” and γωνία, gonía, “corner, angle”) is a six-sided polygon or 6-gon.

The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°..

## What is a 99 sided shape called?

Polygons with 21 to 99 sides have a different system. Take the prefix for the tens digit (found on the left column), the ones digit (right column below), and then stick a “kai” between them to get (tens)kai(ones)gon . The 3-digit sided polygons are named in a similar fashion. A 100-sided polygon is called a hectogon.

## Why are the following figures not a polygon?

A polygon is a closed figure, formed by segments, and its sides do not cross. … The following figures are not polygons because they are not closed. The following figure is not a polygon because its sides cross in the middle.

## What makes a shape a polygon?

A polygon is a closed figure where the sides are all line segments. Each side must intersect exactly two others sides but only at their endpoints. The sides must be noncollinear and have a common endpoint.

## What’s a 12 sided shape called?

dodecagonIn geometry, a dodecagon or 12-gon is any twelve-sided polygon.

## What is a 4 sided shape called?

quadrilateralPolygon. 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 so on.

## What’s a 13 sided shape called?

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

## What is not a polygon shape?

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. Instead, it is two polygons, two triangles.

## Is a rhombus a square?

Lesson Summary. A rhombus is a quadrilateral (plane figure, closed shape, four sides) with four equal-length sides and opposite sides parallel to each other. … All squares are rhombuses, but not all rhombuses are squares. The opposite interior angles of rhombuses are congruent.

## Is Triangle a polygon?

A three-sided polygon is a triangle. There are several different types of triangle (see diagram), including: Equilateral – all the sides are equal lengths, and all the internal angles are 60°.

## What is a 19 sided shape called?

EnneadecagonIn geometry an enneadecagon or enneakaidecagon or 19-gon is a nineteen-sided polygon.

## What is a non example of a polygon?

In addition: Note that polygons are two-dimensional, (planar) and that the segments are straight lines, so any shape which includes an arc is not a polygon. (A circle is therefore not a polygon).

## What is a 100 sided shape called?

hectogonIn geometry, a hectogon or hecatontagon or 100-gon is a hundred-sided polygon. The sum of all hectogon’s interior angles are 17640 degrees.

## What is a 15 sided shape?

pentadecagonIn geometry, a pentadecagon or pentakaidecagon or 15-gon is a fifteen-sided polygon.

## Can a polygon be open?

Polygons can be classified as open or closed. A polygon is open when the segments do not all connect at the beginning and end. That is, if we draw the polygon starting at one point, we finish drawing at a different point.