I need some help

Hello I am writing a whole program which is analyz a elegtromagnetic wave. This is ok but in the program I use a lot of constant for example pi,epsilon etc. I want to ask that how I use a constant in Haskell ? However the user of the program give some argument then program is starting. And I want to use this arguments for example at the end of the program. What will I do. Thanks Baha Electrical & Electronics Engineer Bahadır SEVİNÇ Fırat University Informatics Department & Computer Center Elazığ / Türkiye 23169 Tlf: +90 424 2370000-5011