Definition of a subtended angle  the angle created by an object at a given external point
Math Open Reference

Similar triangles  all three sides in same proportion. SSS
Math Open Reference

Similar triangles  two sides in same proportion, included angle the same. SAS
Math Open Reference

Definition of a segment of a circle.
Math Open Reference

Definition and properties of a secant
Math Open Reference

Definition and properties of scalene triangles
Math Open Reference

A complex figure has some hidden triangles
Math Open Reference

Definition of a opposite rays  two rays with a common endpoint that form a straight line .
Math Open Reference

Definition and properties of isosceles triangles
Math Open Reference

Included side definition: The common leg of two angles.
Math Open Reference
