Set a random position as a circular shape with a custom radius

Hey there, how i can set a models in position like this with custom radius,

If I understand the problem correctly, the ‘random’ is the number of objects you want to show?

If so, the angle between the objects using the center of the circle is A=Math.PI*2/n radians, where n is the number of objects. So if r is the radius:

for(var i=0;i<n;i++){
posx=Math.sin( i * A)*r;
posy=Math.cos(i * A)*r;