1. 12.1
Tangent Lines

2. 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

3. 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

4. 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.

5. 12.1 – Tangent Lines
ML and MN are tangent to circle O. What is the value of x?
117° x° L N O M

6. 12.1 – Tangent Lines
Find x O E D
38° x°

7. 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.

8. 12.1 – Tangent Lines Is ML tangent to circle N and point L? N M L 2524 7

9. 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

10. 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.