Cut a shape out of a plane

if I create a new plane e.g.
new THREE.PlaneGeometry( 5, 20, 32 );

if i wanted to cut a shape out of it, is it possible?

This question was already asked at stackoverflow:

Thanks, I did see that, I guess I was being stupid and hoping thatt there maybe a .holes.push like in shape since I see planes as 2d

Then feel free to use a rectangular shape with holes.