Answer:
The correct option is (b).
Step-by-step explanation:
Given that,
The radius of the circle, r = 8 cm
The area of the sector, [tex]A=56\pi \ cm^2[/tex]
We need to find the measure of the sentral angle. The formula for the area of a sector is given by :
[tex]A=\dfrac{1}{2} r^2\theta[/tex]
Where
[tex]\theta[/tex] is the central angle
Substitute all the values,
[tex]\theta=\dfrac{2A}{r^2}\\\\\theta=\dfrac{2\times 56\pi }{8^2}\\\\\theta=\dfrac{7\pi}{4}\ rad[/tex]
So, the correct option is (b).