How many edges does a triangle have?

Three. It doesn't matter how long the length of each side is or how it's shaped - it will always be three. Here is how one looks like:

Ignore the values of the length of each side, as those are not important. This triangle is not equilateral, however it is still considered a triangle. Only the special kinds of cases are with right triangles - they have some common properties that normal triangles don't.