This resource shows how I would remix "Classifying Triangles" from Illustrative Mathematics (https://tasks.illustrativemathematics.org/content-standards/tasks/1167) 

The original resource asks students to determine where a third point could be to create a right triangle, an obtuse triangle, and an acute triangle.

Instead of having the students choose the first two points, I would remix this activity to actually give the ordered pairs for the starting points on a coordinate plane.  Then I would have the students answer the same questions given in the resource with 3 different examples.  For example, #1 Point A is at (1,1) and Point B is at (4,7).  #2 Point A is at (1,1) and Point B is at (8,1), etc. 

I would also print out the worksheet with a coordinate plane.  Students can slide the worksheet into a dry-erase sleeve so that they can easily investigate various points to answer each question.