Chapter 1 - Tools of Geometry - 1-8 Perimeter, Circumference, and Area - Practice and Problem-Solving Exercises - Page 66: 44

$9346.2\ mm^2$

Find the area of the large circle and deduct the area of the small unshaded circle to find the shaded area. The radius of a circle is half the diameter, so the radius of the large circle is 60 mm, and the area of the small circle is 25 mm. $A_1=\pi r^2=\pi(60^2)=\pi(3600)=11309.7$ $A_2=\pi r^2=\pi(25^2)=\pi(625)=1963.5$ $A=A_1-A_2=11309.7-1963.5=9346.2$