Compound Circular Region

What is Compound Circular Region?

A region whose boundary is built from more than one simple piece, typically some combination of arcs, radii, chords and straight edges belonging to different circles or to a circle and a polygon. Its area is found by decomposing it into sectors, triangles and segments and then adding or subtracting those areas, while its perimeter is found by tracing the outline once and summing only the pieces actually on the outside, so that any edge lying inside the region contributes to neither the perimeter nor a double count of area.

This definition is part of the Circular Measure chapter in Cambridge O Level Additional Mathematics.

Concepts related to Compound Circular Region

• decompose then combine
• concentric arcs
• semicircle as a sector of angle \(\pi\)