Sector is a part of a circle bounded by two radii and the arc between them.
Arc is a part of the circumference that corresponds to a central angle.
Arc length
$$l=\frac{\alpha}{360^\circ}\times 2 \times \pi \times r=r\times\theta$$
where,
l— arc length;
α— central angle in degrees;
θ— central angle in radians;
r— circle radius.
Sector area
$$S=\frac{\alpha}{360^\circ}\times \pi \times r^{2}=\frac{1}{2}\times r^{2}\times\theta$$
where,
S— sector area;
α— central angle in degrees;
θ— central angle in radians;
r— circle radius.
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