shadow cube

openscad

// http://budweiser.cadstudio.cz/2015/08/shadow-cube-3d-model-of-c-d.html

$fn=100;

S=10; // size in mm

// "C" "A" "D" - modelled letters

intersection() {
 M("A", S); // "A"
 translate([0, S, 0])rotate([90, 0, 0]) M("D", S); // "D"
 translate([-S/2, S/2, 0])rotate([90, 0, 90])M("C", S); // "C"
 }

 module M(t,s) {
 resize([s, s, s])linear_extrude(1) text(t, halign="center", font="Raavi:style=Bold");
 }