What is the surface area of a cylindrical ring if its outside diameter is 16 mm and its inside diameter is 10 mm Round your answer to the nearest whole number.?

To find the surface area of a cylindrical ring, we can use the formula for the lateral surface area of a cylinder, which is ( 2\pi h(r_2 + r_1) ), where ( r_2 ) and ( r_1 ) are the outer and inner radii, respectively, and ( h ) is the height. The outer radius ( r_2 ) is 8 mm (half of 16 mm), and the inner radius ( r_1 ) is 5 mm (half of 10 mm). Without a specified height, let's assume a height of 1 mm for calculation purposes. Plugging in the values, the surface area is approximately ( 2\pi(1)(8 + 5) \approx 81 ) mm² when rounded to the nearest whole number.