cossincalc

https://github.com/molte/cossincalc_offline

CosSinCalc is a web application able to calculate the variables of a triangle. The live site is located at http://cossincalc.com/. This is an offline version of the calculator. You can use the included command line utility to generate a PDF page containing all the results, formulae and a drawing of the triangle, or you can include it as a library in your Ruby application and use just the features you care about.