Well because the line segment runs from the center of the circle to a point on the circumference, AB would represent the radius.
First, find out how much 
of 
is.
Now, just add that to .
There are 
members now.
So the problem ask to find and convert the area into square meters. So to convert is you must do the cross multiplication process that could cancel out unit and made the answer into a square meter, so the answer would be 1. x10^-12m^2. I hope you are satisfied with my answer and feel free to ask for more
