A circle with radius 4 has a sector with central angle of 8/5pi radians.

Answer:
(64/5)π units²
Step-by-step explanation:
The area of this sector would be:
Given central angle
------------------------------ *(area of whole circle)
2π rad
In this case, the area of the sector is:
(8/5) π rad
------------------------------ * π(4 units)^2
2π rad
and this reduces to:
(4/5) * π*16 units² or (64/5)π units²