A) 20 cm
B) 25 cm
C) 36 cm
D) 40 cm
Correct Answer: B
$ \Rightarrow $ Area of sector $ =\frac{Area,of,circle}{4} $
$ \Rightarrow $ $ \pi r^{2}( \frac{\theta {}^\circ }{360{}^\circ } )=\frac{\pi r^{2}}{4} $
$ \Rightarrow $ $ \theta {}^\circ =\frac{360{}^\circ }{4}=90{}^\circ $
$ \because $ Area of circle $ =\pi r^{2} $
$ \Rightarrow $ $ 154=\pi r^{2} $
$ \Rightarrow $ $ r^{2}=\frac{154\times 7}{22} $
$ \Rightarrow $ $ r=7 $
Perimeter of sector
$ =\frac{2\pi r\theta }{360{}^\circ }+2r=\frac{2\pi r\times 90{}^\circ }{360{}^\circ }+2r $
$ =\frac{\pi r}{2}+2r=\frac{\pi \times 7}{2}+2\times 7 $
$ =11+14=25,cm $