Inscribed Angle

$\begin{figure}\begin{center}\BoxedEPSF{CentralInscribedAngle.epsf}\end{center}\end{figure}$

The Angle with Vertex on a Circle's Circumference formed by two points on a Circle's Circumference. For Angles with the same endpoints,

$\begin{displaymath} \theta_c=2\theta_i, \end{displaymath}$

where $\theta_c$ is the Central Angle.

See also Central Angle

References

Pedoe, D. Circles: A Mathematical View, rev. ed. Washington, DC: Math. Assoc. Amer., pp. xxi-xxii, 1995.