FOR RUNNING THE PROGRAM (I still don't know a foolproof way of doing this on any machine): To run the program, I believe (I'm possibly entirely wrong) all you have to do is download the .jar executable file "Trigonometer.jar", and if you have Java installed it should just run.

A few friends have tried running it and it failed, even though they had Java installed, I found however that if they also installed the Java dev kit (JDK, just google it) it magically worked.

Either way, all code is in ".src" so someone smarter than me can figure out how to get Java to work properly on their machine.

FOR USING THE PROGRAM: If you have successfully opened the program by some miracle, you will see two triangles with input fields for angles and sides. One triangle is right-angled, and the other is not. Fill in the known values, click "calculate" and boom, it will calculate the missing values for those triangles. If the output seems wrong, your input values were likely meant for the other triangle, like using a 90-degree angle when one is already defined on the right triangle. (In my experience, the output is only technically incorrect if the user has done something wrong, there should be no mathematical bugs).