They are talking about looking at an umbrella like its a circle. The radius is 11 units. That is from the center to the edge.
Consecutive means "in a row" or "next to each other" The 12 "ribs" are the like skeleton structure in the umbrella. But they cut the umbrella into 12 areas. They are asking for the area of one "slice". It is 1/12 of the area of the whole circle.
Seven tenths of every mile she goes she runs. So we would multiply 4 by seven tenths and get 2.8 miles. And to find out how many miles she walks, we would multiply 4 by three tenth and get 1.2