Angles Formed Outside a Circle

Special Segments in a Circle

The Tangent–Chord Angle

Tangents to a Circle

Two Chords Meeting Inside a Circle

Central Angles and their Arcs

The Circle

Line and Rotational Symmetry

Arcs and Chords

Rotation about a Fixed Point

Composition of Translation and Reflection

Reflection over a Line

Translation

Parallel Lines and Proportional Parts

The Triangle Midsegment Theorem

The Angle Bisector Theorem

Special Segments in Similar Triangles

Similarity of Triangles

Similar Polygons

Why we Say "Right Angle" but "Acute Angles" for Triangles Types?