You do not need to do all those calculations.
Create an module of one object at the distance from center and angle you want.
Then rotate the number of modules you need using a for loop
SAMPLE CODE:
pathRadius=15;
num=5;
objHeight = 20;
objDia = 5;
module cylObj()
{
translate([pathRadius,0,objHeight/2]) //move out 15 from center
rotate([0,-28,0]) // rotate 28 degrees
cylinder(h = objHeight, d =objDia,center= true, $fn = 32); //object
}
//for(variable = [start : increment : end])
for(i = [1:1:num]) // 5 objects 1 to 5
{
rotate([0,0,i*(360/num)]) // rotate 360 degrees / 5 objects
cylObj(); // object to rotate
}