Table of Contents || List of Constructions
This and the following pages show constructions that
children and teachers DOING geometry will make
using the Percentage Circle.
The whole circle can be subdivided by drawing diameters.
Draw at random two or more diameters. These are the longest chords of a circle. Thales was the first to discover that a line passing through the center of the circle divides the circle into two equal parts.
Observe: However many times diameters are drawn, the sum of the central angles is 360° .
Each sector made by a single diameter is 180° .
A central angle is an angle whose vertex is located at the center of a circle. The diameter of a circle creates a central angle.
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