Honors Section 9-2. Tangent lines. Definition- a line in the plane of a circle that intersects the circle in exactly one point (pt. of tangency). Thm. 9-1 – If a line is tangent to a circle, then the line is perpendicular to the radius drawn to the point of tangency. m.
Circle O has a tangent line, m, so OX is perpendicular to m.
What kind of triangle is OXZ?