Stage 18 · Circles

18.5 Tangent Lines — The Line That Only Kisses Once

Dig deep into the borderline case of tangency, mastering a tangent's properties, its test, and the tangent-length theorem, then apply them to a triangle's inscribed circle.

5 knowledge points

Knowledge point pages

18.5.1 A Tangent's Property: The Radius Must Be Perpendicular 18.5.2 The Test for a Tangent: Perpendicular Means Tangent 18.5.3 The Tangent-Length Theorem 18.5.4 A Triangle's Inscribed Circle 18.5.5 Incenter Versus Circumcenter, Side by Side

eastmath.com · 18.5 Tangent Lines — The Line That Only Kisses Once