The same length.
It's a shape with many sides where all the sides are the same length.
This shape is called an icosikaitera. All of the sides of the icosikaitera are all of the same equal length.
the shape is a regular shape if it has all the same angles and side lengths.
An octogan It wouldn't be an octogan unless all the sides were the same length. OCTO means 8
A square or a rhombus
it is three sides all with the same length