Reflection
The left pie chart (3D) above shows us the same datum as the right one (2D). But we may have a wrong perception that item C appears to be at least as large as item A, whereas in actuality, it is less than half as large.
Since the datum in a pie chart depend on the angle in a circle. So when we make pie charts into 3D, the data which is closer to us will seem larger.
Here is another example. In the below picture, Steve Jobs put Apple closest to us in the 3D pie chart, which made the percent much bigger than it should be. It appeared to be two-third of RIM (blue) which actually was approximately twice as large as Apple.
Since the datum in a pie chart depend on the angle in a circle. So when we make pie charts into 3D, the data which is closer to us will seem larger.
Here is another example. In the below picture, Steve Jobs put Apple closest to us in the 3D pie chart, which made the percent much bigger than it should be. It appeared to be two-third of RIM (blue) which actually was approximately twice as large as Apple.
Reference
https://www.boundless.com/statistics/textbooks/boundless-statistics-textbook/frequency-distributions-4/frequency-distributions-for-qualitative-data-21/misleading-graphs-107-98/
http://stats.stackexchange.com/questions/109076/what-is-your-favorite-statistical-graph
http://stats.stackexchange.com/questions/109076/what-is-your-favorite-statistical-graph