Area

let $A_y$ be the area of the yellow region

$A_y=\pi (6^2-3^2)=27\pi=27(3.1416)=84.82$

we know that , the area of a circle is = τ $r^2$

so, the area of the large circle is = τ $6^2$ = 36 τ

and the area of the small circle is =τ $3^2$ =9τ

so, the area of the yellow region is = 36 τ -9τ = $27 \times 3.1416$ .........................[ τ=3.1416]

                                                                      =84.82