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.

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.

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