The circular face of a watch has an area that measures between 800 and 900 square millimeters. What could be the radius of the watch face? Use 3.14 for.

A = pi * r^2

800 = 3.14 * r^2

800/3.14 = r^2

255 = r^2

sqrt 255 = r

15.9 rounds to 16mm = r

check ...

A = 3.14 * 16^2

A = 3.14 * 256

A = 803.84 ... thats in between 800 and 900

so ur answer, I believe, is 16mm because 17mm would be too much and 15mm wouldn't be enough

Answer

The radius of the face would lie between 15.96 mm and 16.93 mm.

Explanation

The area of a circle is given by;

Area = πr²

Where area = 800,

πr² = 800

r² = 800/3.14

=254.777

r = √254.777

= 15.96 mm

When area = 900

πr² = 900

r² = 900/3.14

= 286.624

r = √ 286.624

= 16.93 mm

The radius of the face would lie between 15.96 mm and 16.93 mm.