Angle of the dangel???

I had my 12wk ultrasound today. I have an ultrasound every visit due to a large cyst we are following. The tech did a method called angle of the dangel to determine the sex. Pretty much the angel measurement of the genitalia from the spine. Males are a wider angel than girls. My tech said 75-80% boy. I've read it's pretty accurate. Anyone had experience with this method?????