Plano-metric drawings have horizontal lines at what angle?

Please go to: http://74.125.47.132/search?q=cache:QkGvNUzz8LsJ:gscvcevcom.wikispaces.com/file/view/planometric-views.ppt+planometric&hl=en&ct=clnk&cd=8&gl=us Then on the top of the page click on: http://gscvcevcom.wikispaces.com/file/view/planometric-views.ppt. Then view the slide show. Enjoy.