ok so basically what you do is
the whole circle is 360 degrees
100/360 of it is shaded
find 100/360 of the area of the whole thing
100/360=10/36
area=pir^2
d/2=r
5.1/2=r=2.55
aprox pi=3.141592
area=3.141592*(2.55)^2
area=20.42820198
not multiply by 10/36
204.2820198/36
5.67450055
round
5.7
answer is 5.7cm^2
