Secant Radius Diameter Chord Tangent Name the term that best describes the notation. Secant Radius Diameter Chord Tangent

TANGENT = a LINE that intersects the circle exactly ONE time

Common Tangents http://www.ies.co.jp/math/java/geo/comtan/comtan.html

YOUR TURN 3 common tangents 0 common tangents 1 common tangent

More Pythagorean Theorem type problems! Yeah!!  Point of Tangency If a line is tangent to a circle, then it is perpendicular to the radius drawn to the point of tangency More Pythagorean Theorem type problems! Yeah!! 

1. Find x 9 x A B 12 leg2 + leg2 = hyp2 92 + 122 = x2 x = 15

RQ = 16 2. Find RQ leg2 + leg2 = hyp2 P 12 8 R Q 122 + x2 = (8+12)2

leg2 + leg2 = hyp2 r2 + 482 = (r+36)2 r=14 YOUR TURN!!! Find PT leg2 + leg2 = hyp2 r2 + 482 = (r+36)2 P r2 + 2304 = r2 +72r+1296 r r r=14 36 T 48 U

R S If two segments from the same exterior point are tangent to a circle, then they are congruent. T Party hat problems!

3. Find x R S T

4. Find x A C B

YOUR TURN Find x A C B