Deleting points in a contour

I am attempting to clean up my contour that has unneeded points in it but have not found a method that allows me to delete a single point in the contour, causing the path to now be drawn from point 1 to point 3.

Ex:
[1,1]
[1,2]
[2,2]
[2,1]

If I want to turn the above square into a triangle, what is the best way to do this?