You are given (x, y) cordinates of each vertex of a triangle how would you use the slope formula to determine if a triangle in the cordinate plane is a rigt triangle

In a right triangle there are 2 legs and a hypotenuse.  The way you can tell if it's a right triangle is by finding the slope of both the legs.  If their slopes are opposite reciprocals of each other, then they are perpendicular.  By definition, perpendicular lines meet to create a right angle.

What you have to do is subtract then divide.

The second option.