Answer:
Ok so what you should is first find the area for both of the circle

Big circle
you are given the radius which 14mm

Small circle
you are given the diameter of the small circle which 14mm
radius = diameter/2
14/2=7mm

Shaded area means the difference between the 2 areas, in my opinion
so you do 615.44 - 153.86 = 461.58 mm^2
Hope that answers your question
Don't hesitate to comment if you are confused about something :)
Explanation: