Angles subtended by opposite arcs
When a quadrilateral is inscribed on a circle, the angles that are opposite each other are related.
Measure ∠D and ∠F. What do they add up to? Move the points around and try again.
congruency of triangles
Introduction to straight line graphs
Calculus - Gradient of Curves at a Point
Angles subtended by the same arc
Central and inscribed angles subtended by the same arc
An inscribed angle subtended by a diameter
The Quadratic Function
Angles Subtended at Centre and Circumference