A world class slalom skier, shows us the phases of the arc.

 A perfect turn set up, early angles, balanced above the gate.

Now it is time to really get around the gate, so flexing or bending the legs takes pressure off the skis, so the skis can be tipped to high angles, which in turn, increases pressure.

Keep tipping the feet and the skis will arc, hold the upper body in the counter acted relationship to finish the arc.

This is a perfect modern world cup turn, not very complicated, if you know what's happening. Every skier can learn from the best.