Given two moving bodies A and B in the world frame W, how do I compute the position of B, given the position of A and the distance d from A to B?

I am trying to compute the position of an obstacle (B) in the configuration space of a robot. The robot position (A) in the configuration space (W) is known, and the distance (d) from the robot to the obstacle is obtained using range sensors. Please, how do I compute the position of the obstacle (B) and also predict the next position of the obstacle (B') at a given time? I also need sample implementation code in MATLAB.

[Image Analyst]

Uh, how about the Pythagorean theorem?

For prediction I think you have to make a histogram of what directions that B has moved in in the past. If it most likely continues straight, then predict that. Anyway, for any current position of B you can get a probability distribution of what direction it will move next based on how it moved in the past.

[BEN AYAWLI]

Thanks. Please, can you help me a sample implementation in MATLAB?