Question

What is the measure of 0 ?

Answer 1

Option A. 4 radians

Explanation:

step 1

Find the circumference of the circle

The circumference is equal to

`C=2\pi r`

we have

`r=5\ cm`

substitute

`C=2\pi (5)`

`C=10\pi\ cm`

step 2

Find the measure of angle
`\theta`

we know that

The circumference of the circle subtends a central angle of 2π radians

so

using proportion

Find out the central angle by an arc length of 20 cm

`(10\pi)/(2\pi)=(20)/(x)\\\\x=2\pi (20)/10\pi\\\\x=4\ radians`