"When you get around to selecting a chart type in PowerPoint, if you want to mislead or distort, choose dimensional pies or bars. It’s virtually impossible to make a 3D chart that doesn’t give a wrong impression.
In a 3D pie chart, the slice with the thickest edge will always seem larger than its true percentage.
In a 3D bar chart, it’s a challenge to find a rotation at which the short bars are still visible but the tall bars aren’t distorted by the perspective. Judging the heights of bars in a perspective view is a real challenge. So your audience can’t reliably estimate values (do visual take-offs) from your dimensional bars."