Question

Explain how a triangle is a special kind of polygon?

Answer 1

Hint: Triangle is a special kind of polygon as it is the polygon that can be formed using the least number of sides which are required to form a polygon. The minimum number of straight lines required to form a polygon is $3$ and a polygon formed with it is called a triangle.

Complete step by step solution:
Here we need to show why a triangle is a special kind of a polygon. Polygon is any two dimensional shape that is made by using straight lines and the shape so formed must be a close shape. Hence we must know the minimum of three sides that can be used. So the polygon that can be formed using such three sides can be a triangle.

So here we can see that we have used the three straight lines $AB, AC, BC$ which are attached and form a triangle $ABC$.
Polygons are special as they are always closed and composed of the line segments that are joined to form a closed shape as per to form a polygon. The polygons start with the three sides which are known as a triangle. Hence it is special as all others have more sides than what a triangle has.
Due to all these features triangle is a special type of polygon.

Note:
A regular polygon is one in which all the sides and angles are equal. The sum of all the interior angles of the regular polygon is given by $(n - 2) \times 180^\circ $ and here $n$ is the number of sides of that polygon.