b = 0;
c = 0;
degree = 22.5;
width = 13;
length = 1.95;
outerCircle = 80;
innerCircle = 55;
 difference(){
    circle(outerCircle);
     circle(innerCircle);
     for (number = [1 : 1 : 16]){
     rotate([0,0,number * degree]) translate([outerCircle,b,c]) square([width, length], true);
         }
     
     
     
 }