Abc is reflected about the line y= -x to give abc with vertices a (-1,1) b (-2,1) c (-1,0) what are the vertices of abc

  (-1, 1), (-1, 2), (0, 1)

Step-by-step explanation:

It appears as though letter designations have become confused. If not, your question answers itself, as a, b, c are given and you're asking for a, b, and c.

___

Reflecting the given points across the line y=-x transforms them like this:

  (x, y) ⇒ (-y, -x)

That is, you swap the coordinates and negate them both. The result will be as shown above and in the attachment.