Well he doesn't have to know WHAT sine, cosine, and tangents are to make something that can display those values. I wouldn't brag too much about being able to calculate sine cosine and tangent because it can be done by including one extra header file, and by using a single function for each. Ex:
Code:
#include <iostream>
#include <stdlib.h>
#include <math.h>
int main()
{
std::cout<<"Sine of a 45 degree angle is: "<<sin(45)<<std::endl;
system("PAUSE");
return 0;
}
Tangent's function is tan() and cosine's function is cos(). But as for wanting to make programs with a GUI for windows, how about the Win32 API? Read up on that, it's not too tough but if you only know how to output to the screen, declare variables, and make basic functions of your own, I would wait a while.