Describe the techniques employed when showing quantitative differences between Bar and Pie Charts

Describe the techniques employed when showing quantitative differences between Bar and Pie Charts.

Lesikar, R., Flatley, M., &Rentz, K. (2008).Business communication. (11 ed., pp. 421-429). The McGraw-Hill Companies.

(Lesikar, Flatley&Rentz, 2008)