Respuesta :

Answer:

Hence the area of shaded region is 25.12 square inches.

Step-by-step explanation:

We are asked to find the area of the shaded region i.e. we need to find the area of the annulus region.

The radius of the inner circle(r) is [tex]\dfrac{7}{2}[/tex] inch.

and that of the outer circle(R) is [tex]\dfrac{9}{2}[/tex] inch.

since the diameter of the outer circle is 9 inch and hence its radius is [tex]\dfrac{9}{2}[/tex] inch.

similarly the radius of inner circle is: radius of outer circle-1 inch.

Hence the area of the shaded region is given by:

Area of the outer circle-Area of inner circle

Area of outer circle= [tex]\pi R^2[/tex]

and Area of inner circle=  [tex]\pi r^2[/tex]

Hence the area of shaded region= [tex]\pi R^2-\pi r^2=\pi (R^2-r^2)[/tex]

                                                        [tex]=3.14\times ((\dfrac{9}{2})^2-(\dfrac{7}{2})^2)[/tex]

                                                      [tex]=3.14\times (\dfrac{81}{4}-\dfrac{49}{4})[/tex]

                                                      [tex]=3.14\times \dfrac{32}{4}[/tex]

                                                      [tex]=3.14\times 8\\\\=25.12[/tex]

Hence the area of shaded region is 25.12 square inches.