What is the diameter length of a circle with an circumference of 16pi in.

On ryan's last social studies test there were two types of questions true/false worth 3 points each and multiple choice questions worth 4 points each

Which option identifies how kevin should proceed in the following scenario? four years ago kevin designed an mp3 player for young children. now that technology has changed, he would like to update his design to ensure that it encompasses cutting-edge techniques. by creating a third-angle projection of his ideas by designing an isometric projection of his new ideas by referring to past designs and illustrations of his original model by conferring with engineers who have improved upon similar devices

Does y+x=1 show direct variation. yes or no.