What determines the angle that a shock will form? If you look at a lambda shock, you’ll see it isn’t straight up, but with an angle (both the front and rear part of the lambda shock). 

The second comment on [this](https://aviation.stackexchange.com/a/102746/70478) answer helped me, but what is meant by “turning”? 

Basically I was curious why some shocks are curved, others are straight up, (relative to the wings surface) and some are straight but angled, (also relative to the surface of the wing) if that makes sense. Thanks.