Question

the circular face of a watch has an area that measures between 800 and 900 square millimeters.what could be the radius if the watch face

Answer 1

The answer is C: 16 mm

Explanation:

Just took the test and got it right

Answer 2

For the above question options are missing, so the option for the question is

14 mm

15 mm

16 mm

17 mm

The radius of the watch face is 16 mm, if the circular face of a watch has an area that measures between 800 and 900 square millimeters.

Explanation:

The given is,

Circular face of a watch has an area 800 - 900 square millimeters

Step:1

Formula area of circle,

`A = \pi r^(2)`.............................(1)

Where, r - Radius of circle

`\pi = 3.14`

Step:2

From the given options

Check for r = 14 mm

Area,
`A = \pi r^(2)` =
`(3.14)(14)^(2)`

A = 615.44 square millimeters

Area is less than the 800 - 900 square millimeters, So 14 mm could not be radius of the watch face.

Check for r = 15 mm

Area,
`A = \pi r^(2)` =
`(3.14)(15)^(2)`

A = 706.5 square millimeters

Area is less than the 800 - 900 square millimeters, So 15 mm could not be radius of the watch face.

Check for r = 16 mm

Area,
`A = \pi r^(2)` =
`(3.14)(16)^(2)`

A = 803.84 square millimeters

Area is in between the 800 - 900 square millimeters, So 16 mm could be radius of watch face.

Check for r = 17 mm

Area,
`A = \pi r^(2)` =
`(3.14)(17)^(2)`

A = 907.46 square millimeters

Area is greater than the 800 - 900 square millimeters, So 17 mm could not be radius of watch face.

Result:

The radius of the watch face is 16 mm, if the circular face of a watch has an area that measures between 800 and 900 square millimeters.