A cylinder has no straight edges
It has 12 straight edges
a pyramid has 4 straight edges
all of its edges are straight
There are 12 straight edges in a cube. :)
There are three straight edges in a triangle.
Your answer depends on the cut of the diamond in question.
There are no straight edges in a sphere, it is basically a 3-D circle
12 edges
There are four straight edges in a square. All of them are parallel and congruent too.
4 Verticies, 4 edges
8 edges.