Circle Segment 47Cb63
1. **Stating the problem:**
Given a circle with center O, radius AO = 21 cm, and central angle \(\angle AOB = 60^\circ\), we want to analyze the properties of segments and arcs related to this setup.
2. **Formula and rules:**
- The radius of the circle is \(r = AO = 21\) cm.
- The central angle \(\theta = 60^\circ\).
- The length of the arc \(AB\) is given by \(s = r \times \theta\) in radians.
- Convert degrees to radians: \(\theta_{rad} = \frac{\pi}{180} \times 60 = \frac{\pi}{3}\).
- The chord length \(AB\) can be found using the formula \(AB = 2r \sin(\frac{\theta}{2})\).
3. **Calculate the arc length \(AB\):**
$$
s = 21 \times \frac{\pi}{3} = 7\pi \approx 21.99 \text{ cm}
$$
4. **Calculate the chord length \(AB\):**
$$
AB = 2 \times 21 \times \sin\left(\frac{60^\circ}{2}\right) = 42 \times \sin(30^\circ) = 42 \times 0.5 = 21 \text{ cm}
$$
5. **Interpretation:**
- The radius segments AO and OB are each 21 cm.
- The chord AB is 21 cm.
- The arc length AB is approximately 21.99 cm.
- The sector AOB corresponds to a 60° slice of the circle.
**Final answers:**
- Radius AO = 21 cm
- Central angle \(\angle AOB = 60^\circ\)
- Arc length AB \(\approx 21.99\) cm
- Chord length AB = 21 cm
This completes the analysis of the given problem.