Final answer:
A bubble chart is used for displaying three dimensions of data with bubble size as the third dimension, while a radar chart is for displaying multiple dimensions of data on separate axes.
Step-by-step explanation:
The statement that is true about bubble and radar charts is: 1) Bubble chart is used to display three dimensions of data while radar chart is used to display multiple dimensions of data. A bubble chart is a type of scatterplot where a third dimension of data is represented by the size of the bubbles. On the other hand, radar charts, also known as spider or web charts, are used to display multi-dimensional data in a way that is easy to understand; each variable is given its own axis originating from the center, enabling the representation of multiple dimensions.