Particle system shape radius change through script

How do I access the shape radius of a particle system in C#?

float radius = 33f;

ParticleSystem ps = GetComponent<ParticleSystem>();
var sh = ps.shape;
sh.radius = radius;

C# version:

float r = 33f;
ParticleSystem.ShapeModule ps = myEffect.GetComponent<ParticleSystem>().shape;
ps.radius = r;

Unity ParticleSystem Shape reference