How many unique triangles can be drawn with side lengths 4 cm, 6cm, and 8cm?
I think you can make two of them.
As you walk around the triangle in the clockwise direction,
you could encounter the sides in the order of
4cm ==> 6cm ==> 8cm,
or in the order of
4cm ==> 8cm ==> 6cm.
Those two possibilities are mirror images of each other,
so they're not congruent, and they're different triangles.