Answer:
B. 48 cm^2
Explanation:
The area of a circle is
r^2. To find the area of the shaded region find the area of both 5cm and 3cm, both of the circles.
I'll call r = 5 circle a & r = 3 circle b
Circle A area is 78.55 cm^2
Circle B area is 28.278 cm^2
Now minus the area of B from that of A; 78.55 - 28.278 = 50.272
If you don't have a calculator then multiply the radius squared by 3 and if you have time, add a tenth to the total radius and then do the same and then use the process of alimination to remove any answers that seem unlikely and work from there.
A = 75 + 2.5 = 77.5 cm^2
B = 27 + .9 = 27.9 cm^2