The fraction of a circle represented by the shaded region is:
S '/ S = ((8/5) * pi * r) / (2 * pi * r)
Rewriting we have:
S '/ S = ((8/5)) / (2)
S '/ S = 8/10
S '/ S = 4/5
Then, we can make the following rule of three:
(64/5) pi -------> 4/5
x ----------------> 1
Clearing x we have:
x = ((1) / (4/5)) * ((64/5) pi)
Rewriting:
x = (5/4) * ((64/5) pi)
x = (5/4) * ((64/5) pi)
x = 50.24
Answer:
The area of the complete circle is:
x = 50.24
