This is where you learn some systems engineering, rather than just getting some free code. The two driving factors on a program are the inputs and the outputs. First, consider the inputs. There are a number of ways to specify a triangle. You can use 3 points, two points plus an implicit point at the origin, 3 side measures, two side measures plus the angle between the given sides, or a side and the two ending angles. If you don’t care what the size of the triangle is, but care only about the shape, you can specify the triangle by 3 angles only. The next thing to consider is the outputs. Will the triangle be drawn? If so, how? If not, what exactly is the output? Once these things are known, you have an interface spec. After that, decide (or tell us) what the OS and language are.
Linker Systems, Inc.