A triangle has vertices A (2, -2), B (-2, 5), and C (-4, 2).

1) The slope of line segment AB is _____ units.

2) The slope of line segment BC is _____ units.


3) The slope of line segment AC is _____ units.

4) By looking at these slopes, you can tell that triangle ABC is a right triangle, because

(_____)(_____) = _____.