An arc on a circle measures [tex]\( 85^{\circ} \)[/tex]. The measure of the central angle, in radians, is within which range?

A. [tex]\(0\)[/tex] to [tex]\(\frac{\pi}{2}\)[/tex] radians
B. [tex]\(\frac{\pi}{2}\)[/tex] to [tex]\(\pi\)[/tex] radians
C. [tex]\(\pi\)[/tex] to [tex]\(\frac{3\pi}{2}\)[/tex] radians
D. [tex]\(\frac{3\pi}{2}\)[/tex] to [tex]\(2\pi\)[/tex] radians



Answer :

To solve this problem, let's follow these steps:

1. Convert the angle from degrees to radians.
- The arc measure given is [tex]\(85^\circ\)[/tex].
- To convert degrees to radians, use the conversion factor [tex]\(\frac{\pi}{180}\)[/tex].

So, we have:
[tex]\[ \text{Central angle in radians} = 85 \times \frac{\pi}{180} \][/tex]

2. Calculate the central angle in radians.
- Multiplying the degrees by the conversion factor:
[tex]\[ 85 \times \frac{\pi}{180} = \frac{85\pi}{180} \approx 1.4835298641951802 \text{ radians} \][/tex]

3. Determine which range the central angle in radians falls within.
- We have the following ranges to consider:
- [tex]\(0\)[/tex] to [tex]\(\frac{\pi}{2}\)[/tex] radians
- [tex]\(\frac{\pi}{2}\)[/tex] to [tex]\(\pi\)[/tex] radians
- [tex]\(\pi\)[/tex] to [tex]\(\frac{3\pi}{2}\)[/tex] radians
- [tex]\(\frac{3\pi}{2}\)[/tex] to [tex]\(2\pi\)[/tex] radians
- The value [tex]\(1.4835298641951802\)[/tex] radians lies between [tex]\(0\)[/tex] and [tex]\(\frac{\pi}{2}\)[/tex].
- Since [tex]\(\frac{\pi}{2} \approx 1.5708\)[/tex], and [tex]\(1.4835298641951802 < 1.5708\)[/tex], the central angle falls within the first range.

4. Conclusion:
- The central angle, [tex]\(1.4835298641951802\)[/tex] radians, falls within the range [tex]\(0\)[/tex] to [tex]\(\frac{\pi}{2}\)[/tex] radians.

Therefore, the central angle is within the range [tex]\(0\)[/tex] to [tex]\(\frac{\pi}{2} \)[/tex] radians.