Here we use the formula of area of sector, which is
[tex] Area =( \frac{ \theta}{360}) \pi r^2 [/tex]
Substituting 140 for theta, 11 for radius, we will get
[tex] Area = ( \frac{140}{360}) \pi *11^2 [/tex]
[tex] Area = 147.8 inches^2 [/tex]
And that's the required area wiped by the wiper blade .