A:
isoseles
scalene
equilateral
B:
A perfect Cylinder has only a Top-side, a bottom-side and a surrounding side, therefore it counts to three.
Triangles are 3 sided polygons.
It is a triange that has three sides.
triangle
traingel
There is no special name: they are polygons, as are shapes with 3 or 3 million sides.
Polygons are shapes with 3 or more sides
Triangles
Triangles have 3 sides.
A triangle
A Triangle
It is a polygon that has 3 or more sides
Triangles
a triangle
A triangle.
An equilateral triangle.
They are polyhedra.