Circle S is shown. Line segment R T is a diameter. The length of S T is 4. Sector R S T is shaded. The measure of central angle RST is radians. What is the area of the shaded sector? 4Pi units squared 8Pi units squared 16Pi units squared 20Pi units squared.

What are the two main ideas of this passage? museum experts feel that museums must change to attract visitors. museum experts care more about the number of visitors than about history. museums that display artworks and exhibits do not make families welcome. museums like colonial williamsburg make learning about the past fun. museums in the united states are different than in other countries.