C++ :: How To Predict New Compass Angle Of Object With Information

In a cartesian coordinate system, I want to be able to predict a compass angle of an object. So I have a base position of (0,0) and then a distance and compass angle to an object. This object also has a heading and a speed. How can I predict the new compass angle of the object with that information?

my coordinate system is like this:

Code:
0 y
|
|
270-------------- 90 x
|
|
180

I think the first step would be to compute the cartesian coordinates of the object:

float degs_to_rads = 3.141592653589793 / 180.0;
x = distance * sin(angle*degs_to_rads);
y = distance * cos(angle*degs_to_rads);

then the next step would be to compute the predicted x and y from the speed and heading of the object:

predictedx = ??
predictedy = ??

then finally convert back to an angle, and distance:

newDistance = sqrt(predictedx^2 + predictedy^2);
newAngle = atan2(predictedy, predictedx);

fill in the blanks?? Are my other things correct?