1. **Problem:** On a circle of radius 10 m, find the length of an arc subtending a central angle of (a) $\frac{4\pi}{5}$ radians, (b) 110°.
2. **Formula:** Arc length $s$ is given by
$$s = r \theta$$
where $r$ is the radius and $\theta$ is the central angle in radians.
3. **Important:** If the angle is in degrees, convert to radians first using
$$\theta_{rad} = \theta_{deg} \times \frac{\pi}{180}$$
4. **Part (a):** Given $r=10$ m and $\theta = \frac{4\pi}{5}$ radians,
$$s = 10 \times \frac{4\pi}{5} = \frac{40\pi}{5} = 8\pi$$
5. **Part (b):** Given $r=10$ m and $\theta = 110^\circ$,
Convert to radians:
$$\theta = 110 \times \frac{\pi}{180} = \frac{110\pi}{180} = \frac{11\pi}{18}$$
Calculate arc length:
$$s = 10 \times \frac{11\pi}{18} = \frac{110\pi}{18} = \frac{55\pi}{9}$$
6. **Final answers:**
- (a) $8\pi$ meters
- (b) $\frac{55\pi}{9}$ meters
These represent the lengths of the arcs subtending the given angles on the circle of radius 10 m.
Arc Length 3Fb635
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