Arc
An arc is a continuous, unbroken part of the circumference of a circle or any other curve. In a circle, a minor arc is smaller than a semicircle, while a major arc is larger than a semicircle.
Example
The length $l$ of an arc that subtends an angle $\theta$ (in degrees) at the center of a circle with radius $r$ is given by the formula: $$l = \frac{\theta}{360^\circ} \times 2\pi r$$ If $\theta = 60^\circ$ and $r = 7 \text{ cm}$, using $\pi \approx \frac{22}{7}$, the arc length is $l = \frac{60}{360} \times 2 \times \frac{22}{7} \times 7 = \frac{1}{6} \times 44 \approx 7.33 \text{ cm}$.