Polygon abcde rotates 52º about the origin to create polygon
a′b′c′d′e′. if m∠bcd= 31º, what is m∠b'c'd' ?

Rotating the entire polygon should have no effect on its internal angles 

The major difference is that a histogram is only used to plot the frequency of score occurrences in a continuous data set that has been divided into classes, called bins.  bar charts, on the other hand, can be used for a great deal of other types ofvariables  including  ordinal  andnominal  data sets.