A pyramid is a four-sided, three-dimensional figure.
Equilateral triangle.
A scalene triangle
Icosagon is a 20 sided figure.
The name of a four sided figure (or shape) is called a Square. :)
The name that is given to an 8 sided figure is a octogan.
A 5 sided figure is called a: pentagon
A 15-sided figure is called a pentadecagon.
it is a triangle.
The name of am 11-sided figure is a "hendecagon". ---- Also known as an "undecagon".
a 3 sided figure
A 5-sided figure is called a pentagon.