Sine and cosine challenge!

This is a nice software to practise finding the exact values (most of them surds) of sines and cosines for specific angles (multiples of 30 or 45 degrees). The option to display the unit circle on the side is very useful to start and get some experience at first. The circle will show where to find the cosine and sine of acute angles on the horizontal axis and vertical axis respectively, and how to use symmetry to find cosines and sines for any other angle. One can choose between various options including working with degrees, radians or both, and changing the range of angles to ask questions about. The software includes its own user's manual and a very special 'Challenge' mode with increasing difficulty and limited time questions -- do you think you can handle it? Enjoy and try to beat your score!

Watch the software running on Youtube: https://www.youtube.com/watch?v=JZELkdeDcRg.

NB: the file comes with a .pdf extension which should be changed to a .exe extension before running. This can be done by renaming the file, making sure that known file extensions are not hidden: see the 'View' tab of the 'Folder Options' window available from the Control Panel.