Answer:
[tex] A = \dfrac{7}{2}\pi~cm^2 [/tex]
Step-by-step explanation:
There is a formula for the area of a sector given the radius and the angle measure.
[tex] A = \dfrac{n}{360^\circ}\pi r [/tex]
n = angle measure
r = radius
[tex] A = \dfrac{140^\circ}{360^\circ}\pi \times (3~cm)^2 [/tex]
[tex] A = \dfrac{14}{36}\pi \times 9~cm^2 [/tex]
[tex] A = \dfrac{7}{18}\pi \times 9~cm^2 [/tex]
[tex] A = \dfrac{7}{2}\pi~cm^2 [/tex]
