an octogon
A triangle.
A TRIGON , more usually a 'Triangle'.
Triangle is a shape with three sides.
a triangle
a triangle
In a triangle with no sides congruent we call it scalene.
When all three sides of a triangle are congruent, it is called an equilateral triangle.
cube
triangle isosceles triangle
i would call it a square
Isoceles
a shape with nine sides is called nonagon