Scratch

Don't really need the trig functions, just the square root function, sqr[ ]. The equation is:

distance = sqr((old_x - new_x) * (old_x-new_x) + (old_y - new_y)*(old_y - new_y)).

that is, you take the difference between the x's and square the result (multiply it by itself), then take the difference between the y's and square that result, add the two results together, then take the square root.

maybe somebody good at putting scratch blocks into posts can illustrate it better than this.

Well, it's not as simple as you might hope.  You can do it with the Trig function ATAN by giving it the quotient of the difference in X divided by the difference in Y but it gets ugly as it won't tell you what quadrant it is in.  So you end up doing a lot of testing on the sign of the differences of X and Y to get the quadrant correct.  Some languages have a function called ATAN2 (which takes two arguments) which will give you the angle in the correct quadrant.  It would be nice if Scratch implemented ATAN2 someday.  Until then, if you really want it, I can upload a project with the logic in it.  Or, you might want to consider an easier approach, like send a sprite to the location and query the sprite.

Getting the angle and the distance is essentially converting from Cartesian (rectangular) coordinates to Polar coordinates.  I have uploaded a project called Cartesian to Polar on the account I use for demonstrations and repaired projects, Paddle2SeeFixIt.  The link is as follows:

http://scratch.mit.edu/projects/Paddle2SeeFixIt/95622

Let me know if you have any questions.