12.1 Tangent Lines

12.1 – Tangent Lines Goals / “I can…..” Use the relationship between a radius and a tangent Use the relationship between two tangents from one point

12.1 – Tangent Lines A tangent to a circle is a line in the plane of a circle that INTERSECTS the circle in EXACLTY 1 point. The point of intersection is called the point of tangency

12.1 – Tangent Lines If a line is tangent to a circle, then the line is PERPENDICULAR to the radius drawn to the point of tangency.

12.1 – Tangent Lines ML and MN are tangent to circle O. What is the value of x? 117° x° L N O M

12.1 – Tangent Lines Find x O E D 38° x°

12.1 – Tangent Lines A dirt bike chain fits tightly around two gears. The chain & gears form a figure like the one shown. Find the distance between the centers of the gears. 26.5 in. 2.4 in. 9.3 in.

12.1 – Tangent Lines Is ML tangent to circle N and point L? N M L 25 24 7

12.1 – Tangent Lines 2 segments that are tangent to a circle that start from the same point outside the circle are congruent. O C B A

12.1 – Tangent Lines Circle O is inscribed by ABC. Find the perimeter of ABC A F B C E D O 10 in. 15 in. 8 in.