If you know the total legnth of the pipe, then you can get them made to size, then bend them to shape during fitting. Its quite easy. Bend the piped in as wide a radius you can, bending them round your thumbs with your fingers. To tight a radius will knacker the pipe should you kink it. Also, with very tight bends, the copper tends to work harded making it very brittle. Just a little time and care, and you won´t find it too much of a problem.