This document discusses circular measures including radians, arc length of a circle, area of a sector of a circle, and finding the perimeter of a segment of a circle. Several examples and exercises are provided to illustrate how to:
1. Convert between degrees and radians.
2. Calculate arc lengths and angles given the radius and subtending angle.
3. Find the area of sectors given the radius and subtending angle.
4. Determine unknown values such as the radius or angle when given the sector area.
5. Calculate perimeters of circular segments.
Past SPM questions are also presented involving finding angles, radii, or arc lengths based on information provided about circles, arcs, or sectors.