A line graph, or line chart, shows info as a series of data points that are connected by line segments.
The answer is 2500. Hope you get an A+ on whatever you're working on :)
OK, no figure, but from the comment is sounds like the grey area is the big circle minus the small circle.
The diameter of the small circle is 2 so its radius is 1 and its area πr² is π.
The radius of the larger circle is 4, so area 16π
The shaded area is 16π - π
Answer: 15π